Noriko Mizusawa, Nagakatsu Harada, Takeo Iwata, Izumi Ohigashi, Mitsuo Itakura and Katsuhiko Yoshimoto : Identification of protease serine S1 family member 53 as a mitochondrial protein in murine islet beta cells, Islets, Vol.14, No.1, 1-13, 2021.
Shinya Watanabe, Junichi Iga, Shusuke Numata, Masahito Nakataki, Toshihito Tanahashi, Mitsuo Itakura and Tetsuro Ohmori : Association Study of Fat-mass and Obesity-associated Gene and Body Mass Index in Japanese Patients with Schizophrenia and Healthy Subjects., Clinical Psychopharmacology and Neuroscience, Vol.10, No.3, 185-189, 2012.
(要約)
Fat-mass and obesity-associated (FTO) gene is known to be involved in the pathophysiology of obesity and a single-nucleotide polymorphism (SNP) rs9939609 of FTO gene is repeatedly confirmed to be associated with body mass index (BMI) and obesity. The aim of this study is to elucidate effects of FTO gene polymorphism on BMI in Japanese patients with schizophrenia and healthy subjects. Three hundred fifty one patients with schizophrenia and 342 age- and sex-matched healthy subjects participated in the study. Information on BMI and antipsychotic medication was also collected from patients and healthy subjects. Genotype of the FTO SNP rs9939609 was determined by TaqMan SNP Genotyping Assays. There was no significant difference in BMI between patients and healthy subjects. No significant difference in BMI was observed among any medications. We observed no significant difference in rs9939609 allele frequencies between patients and healthy subjects. There was a significant difference in BMI between healthy subjects with risk (AA or TA) genotypes and those with TT genotype. We also observed a significant positive correlation between the number of risk allele (A allele) and BMI in healthy subjects. Our study suggested that FTO rs9939609 polymorphism might have some impacts on the BMI in healthy subjects, but might not have same impacts on the BMI of patients with schizophrenia.
We have previously identified four significant quantitative trait loci (QTL) affecting plasma glucose concentrations on F(2) progeny of hypoinsulinemic diabetic Akita mice, heterozygous for the Ins2 gene Cys96Tyr mutation, and non-diabetic A/J mice, one of which on chromosome 15 named Dbm4 (diabetic modifier QTL 4) was shown to affect fasting plasma glucose concentrations with a maximum LOD score of 6.17. To estimate the influence of Dbm4 itself to the diabetes-related phenotypes, we constructed congenic strain with heterozygous Ins2 mutation using the Akita allele as donor of Dbm4 locus in the A/J genetic background, and measured quantitative traits including plasma glucose concentrations in glucose tolerance test (GTT). In this study, we found the Akita allele in Dbm4 was associated with higher fasting plasma glucose concentrations as in previous QTL analysis. According to gene expression assay, key enzymes of hepatic gluconeogenesis were expressed to the more increased degree in the liver of congenic mice compared to the A/J allele based control mice. Based on these results, we concluded that diabetic modifier gene(s) exist on Dbm4 locus affecting fasting plasma glucose concentrations via regulation of gluconeogenic gene expression in the hypoinsulinemic diabetic condition. Identification of the modifier gene responsible for Dbm4 would provide new drug development targets for human type 2 diabetes with hepatic insulin resistance.
(キーワード)
Animals / Blood Glucose / Body Weight / Chromosome Mapping / Diabetes Mellitus, Type 2 / Disease Models, Animal / Fasting / Genetic Association Studies / Genetic Linkage / Gluconeogenesis / Lod Score / Male / Mice / Mice, Congenic / Mice, Transgenic / Quantitative Trait Loci
Makoto Kinoshita, Shusuke Numata, Atsushi Tajima, K Ohi, R Hashimoto, S Shimodera, Issei Imoto, Mitsuo Itakura, M Takeda and Tetsuro Ohmori : Meta-analysis of association studies between DISC1 missense variants and schizophrenia in the Japanese population., Schizophrenia Research, Vol.141, No.2-3, 271-273, 2012.
(キーワード)
Asian Continental Ancestry Group / Case-Control Studies / Female / Gene Frequency / Genetic Association Studies / Genotype / Humans / Male / Mutation, Missense / Nerve Tissue Proteins / Polymorphism, Single Nucleotide / Schizophrenia
We have previously identified significant quantitative trait loci (QTL) Dbm1 (diabetic modifier QTL 1) on chromosome 6, affecting plasma glucose and insulin concentrations and body weight on F(2) progeny of hypoinsulinemic diabetic Akita mice, with the heterozygous Ins2 gene Cys96Tyr mutation, and non-diabetic A/J mice. To discover diabetic modifier genes on Dbm1, we constructed congenic strain for Dbm1 using the Akita allele as donor in A/J allele genetic background, and compared diabetes-related phenotypes to control mice. The homozygote for Akita allele of Dbm1 was associated with lower plasma glucose concentrations in glucose tolerance test (GTT) in the hypoinsulinemic condition derived from the Ins2 mutation and lower plasma insulin concentrations and body weight in the normoinsulinemic condition without the Ins2 mutation than the homozygote for A/J allele, as we performed QTL analysis on F(2) intercross mice. The Akita allele also decreased the epididymal white adipose tissue (EWAT) weight. According to the analysis of sub-congenic strains, we narrowed down the responsible diabetic modifier region to 9 Mb. As fourteen candidate genes exist in this region, we analyzed genomic variants of these genes and gene expression in the muscle, liver, and EWAT and identified that Bhlhe40 gene expression in muscle is decreased in congenic mice. According to the in vitro functional analyses, Bhlhe40 was shown to negatively control fatty acid oxidation in cultured myocyte. Based on these, we conclude that Bhlhe40 is a possible candidate diabetic modifier gene responsible for Dbm1 locus affecting diabetes and/or obesity through negatively controlling fatty acid oxidation in muscle.
(キーワード)
Adipose Tissue, White / Alleles / Animals / Basic Helix-Loop-Helix Transcription Factors / Blood Glucose / Body Weight / Diabetes Mellitus, Type 2 / Epididymis / Fatty Acids / Female / 遺伝子発現 (gene expression) / Glucose Tolerance Test / Homeodomain Proteins / Homozygote / インスリン (insulin) / Liver / Male / Mice / Muscle Cells / Muscles / Mutation / 酸化と還元 (oxidation and reduction) / Quantitative Trait Loci
Hiroshi Inoue, Tokuo Mukai, Yukiko Yamashita, Chizuko Kimura, Natsumi Kangawa, Mitsuo Itakura, Tsutomu Ogata, Yoshiya Ito and Kenji Fujieda : Identification of a novel mutation in the exon 2 splice donor site of the POU1F1/PIT-1 gene in Japanese identical twins with mild combined pituitary hormone deficiency., Clinical Endocrinology, Vol.76, No.1, 87, 2011.
(要約)
Context: To date, approximately 35 different POU1F1 mutations have been described in patients with familial and sporadic combined pituitary hormone deficiency (CPHD) from different ethnic backgrounds. The majority are missense mutations clustered within the conserved POU-specific and POU-homeo domains, encoded by exons 4 and 6, respectively. Objectives: This study aimed to identify the molecular basis and clinical characteristics of a Japanese CPHD family with a novel POU1F1 mutation. Design: The POU1F1 gene was sequenced in identical twin brothers with mild CPHD. The mutation identified was also evaluated in family members as well as 188 Japanese controls, and then examined in functional studies. Results: A novel heterozygous splice site mutation (Ex2+1G>T; c.214+1G>T) was detected. This mutation was also present in their undiagnosed mother, but not in any of the controls. In vitro splicing studies suggested this mutation to result in an in-frame skipping of exon 2, thus producing an internally deleted protein lacking most of the R2 transactivation subdomain (TAD-R2). Heterologous expression studies of the mutated POU1F1 protein showed only modest reductions of its transactivation activities in HEK293T cells, while acting as a dominant-negative inhibitor of the endogenous activities of POU1F1 in pituitary GH3 cells. Conclusions: This is the first report of a mutation at the exon 2 donor splice site of POU1F1, affecting TAD-R2. The addition of this mutation to the growing list of pathological POU1F1 mutations may provide deeper insights into clinical heterogeneity in the expressions of individual mutations and a better understanding of the structure-function relationships of POU1F1.
Hiroshi Inoue, Yukiko Yamashita, Natsumi Kangawa, Chizuko Kimura, Tsutomu Ogata, Kenji Fujieda, Zhi-Rong Qian, Toshiaki Sano and Mitsuo Itakura : Analysis of expression and structure of the rat GH-secretagogue/ghrelin receptor (Ghsr) gene: Roles of epigenetic modifications in transcriptional regulation., Molecular and Cellular Endocrinology, Vol.345, No.1-2, 1-15, 2011.
(要約)
In the current study, to elucidate the molecular basis of cell type-specific expression of the GH-secretagogue/ghrelin receptor type 1A (GHSR1A), we characterized the structure and putative promoter region of the rat Ghsr gene. We identified an alternative 5'-untranslated first exon that contains multiple transcription start sites, and confirmed a 200-bp sequence proximal to this exon to be sufficient for basal promoter activity. A promoter-associated CpG island conserved across different species was found to be hypomethylated in Ghsr1a-expressing cell lines, while being heavily methylated in non-expressing cells. In cells with low or absent Ghsr1a expression, treatment with demethylating agents activated Ghsr1a transcription. Chromatin immunoprecipitation assays demonstrated Ghsr1a-expressing cells to display active histone modifications, whereas repressive modifications were present exclusively in other cell types. These results suggest epigenetic modifications at GHSR to play important roles in determining GHSR1A expression and abundance, and therefore the consequent sensitivity of cells to ghrelin.
(キーワード)
5' Flanking Region / Animals / Azacitidine / Cell Line / DNA Methylation / Epigenesis, Genetic / Gene Expression Profiling / ゲノム (genome) / Histones / Humans / Hydroxamic Acids / Mice / Organ Specificity / Promoter Regions, Genetic / Protein Processing, Post-Translational / RNA, Messenger / Rats / Receptors, Ghrelin / Transcription Initiation Site / Transcription, Genetic
Hiroshi Inoue, Natsumi Kangawa, Atsuko Kinouchi, Yukiko Yamashita, Chizuko Kimura, Reiko Horikawa, Yosuke Shigematsu, Mitsuo Itakura, Tsutomu Ogata and Kenji Fujieda : Identification and functional analysis of novel human growth hormone secretagogue receptor (GHSR) gene mutations in Japanese subjects with short stature., The Journal of Clinical Endocrinology and Metabolism, Vol.96, No.2, E373-E378, 2010.
(要約)
Four novel heterozygous GHSR1A mutations were identified (ΔQ36, P108L, C173R, and D246A). Expression studies demonstrated that these mutations had varying functional consequences: 1) all mutations showed a loss-of-function effect on the constitutive signaling activity of GHSR1A, but the degree of loss varied widely; 2) C173R caused intracellular retention of the mutated protein, resulting in total loss of receptor function; 3) P108L resulted in a large decrease in binding affinity to ghrelin, without affecting its surface expression; 4) D246A uniquely impaired agonist- and inverse agonist-stimulated receptor signaling; and 5) ΔQ36 showed only a subtle reduction in constitutive activity. The cumulative frequency of these putative functional mutations was significantly higher in the patient group than in controls (4.72 vs. 0.53%; P = 0.019; odds ratio = 9.28; 95% confidence interval, 1.10-78.0).
Véronique Bolduc, Gareth Marlow, M Kym Boycott, Khalil Saleki, Hiroshi Inoue, Johan Kroon, Mitsuo Itakura, Yves Robitaille, Lucie Parent, Frank Baas, Kuniko Mizuta, Nobuyuki Kamata, Isabelle Richard, P Wim H J Linssen, Ibrahim Mahjneh, Marianne Visser de, Rumaisa Bashir and Bernard Brais : Recessive mutations in the putative calcium-activated chloride channel Anoctamin 5 cause proximal LGMD2L and distal MMD3 muscular dystrophies., American Journal of Human Genetics, Vol.86, No.2, 213-221, 2010.
(要約)
The recently described human anion channel Anoctamin (ANO) protein family comprises at least ten members, many of which have been shown to correspond to calcium-activated chloride channels. To date, the only reported human mutations in this family of genes are dominant mutations in ANO5 (TMEM16E, GDD1) in the rare skeletal disorder gnathodiaphyseal dysplasia. We have identified recessive mutations in ANO5 that result in a proximal limb-girdle muscular dystrophy (LGMD2L) in three French Canadian families and in a distal non-dysferlin Miyoshi myopathy (MMD3) in Dutch and Finnish families. These mutations consist of a splice site, one base pair duplication shared by French Canadian and Dutch cases, and two missense mutations. The splice site and the duplication mutations introduce premature-termination codons and consequently trigger nonsense-mediated mRNA decay, suggesting an underlining loss-of-function mechanism. The LGMD2L phenotype is characterized by proximal weakness, with prominent asymmetrical quadriceps femoris and biceps brachii atrophy. The MMD3 phenotype is associated with distal weakness, of calf muscles in particular. With the use of electron microscopy, multifocal sarcolemmal lesions were observed in both phenotypes. The phenotypic heterogeneity associated with ANO5 mutations is reminiscent of that observed with Dysferlin (DYSF) mutations that can cause both LGMD2B and Miyoshi myopathy (MMD1). In one MMD3-affected individual, defective membrane repair was documented on fibroblasts by membrane-resealing ability assays, as observed in dysferlinopathies. Though the function of the ANO5 protein is still unknown, its putative calcium-activated chloride channel function may lead to important insights into the role of deficient skeletal muscle membrane repair in muscular dystrophies.
Koji Muroya, Takahiro Mochizuki, Maki Fukami, Manami Iso, Keinosuke Fujita, Mitsuo Itakura and Tsutomu Ogata : Diabetes mellitus in a Japanese girl with HDR syndrome and GATA3 mutation., Endocrine Journal, Vol.57, No.2, 171-174, 2009.
(要約)
We report on a Japanese girl with HDR (hypoparathyroidism, sensorineural deafness, and renal dysplasia) syndrome who developed diabetes mellitus (DM) at three years of age (blood glucose 713 mg/dL, HbA(1c) 8.0%) in the absence of anti-glutamic acid decarboxylase autoantibodies. Mutation analysis revealed a de novo heterozygous two base pair deletion at exon 6 of the GATA3 gene (c.1200_1201delCA; p.H400fsX506). GATA3 expression was identified by PCR amplification for human pancreas cDNA, and mouse Gata3 was weekly but unequivocally expressed in pancreatic beta cells. The results, in conjunction with the previous findings indicating the critical role of GATA3 in lymphocyte function, GATA3 haploinsufficiency may affect the function of beta cells and/or lymphocytes, leading to the development of DM in relatively exceptional patients with high susceptibility to DM.
Shusuke Numata, Masahito Nakataki, Junichi Iga, Toshihito Tanahashi, Yoshihiro Nakadoi, Kazutaka Ohi, Ryota Hashimoto, Masatoshi Takeda, Mitsuo Itakura, Shu-ichi Ueno and Tetsuro Ohmori : Association Study Between the Pericentrin (PCNT) Gene and Schizophrenia., NeuroMolecular Medicine, Vol.12, No.3, 243-247, 2009.
(要約)
Disrupted-in-schizophrenia 1 (DISC1), a known genetic risk factor for schizophrenia (SZ) and major depressive disorder (MDD), interacts with several proteins and some of them are reported to be genetically associated with SZ. Pericentrin (PCNT) also interacts with DISC1 and recently single-nucleotide polymorphisms (SNPs) within the PCNT gene have been found to show significant associations with SZ and MDD. In this study, case-controlled association analysis was performed to determine if the PCNT gene is implicated in SZ. Nine SNPs were analyzed in 1,477 individuals (726 patients with SZ and 751 healthy controls). No significant difference was observed between the controls and the patients in allelic frequencies or genotypic distributions of eight SNPs. Although allelic distribution of rs11702684 was different between the two groups (P = 0.042), the difference did not reach statistical significance after permutation correction for multiple comparisons. In the haplotypic analysis, we could not find any significant association in our subjects, either. This gene may not play a major role independently in the etiology of SZ in the Japanese population.
Takeo Iwata, Masamichi Kuwajima, Akiko Sukeno, Naozumi Ishimaru, Yoshio Hayashi, Martin Wabitsch, Noriko Mizusawa, Mitsuo Itakura and Katsuhiko Yoshimoto : YKL-40 secreted from adipose tissue inhibits degradation of type I collagen., Biochemical and Biophysical Research Communications, Vol.388, No.3, 511-516, 2009.
(要約)
Obesity is considered a chronic low-grade inflammatory status and the stromal vascular fraction (SVF) cells of adipose tissue (AT) are considered a source of inflammation-related molecules. We identified YKL-40 as a major protein secreted from SVF cells in human visceral AT. YKL-40 expression levels in SVF cells from visceral AT were higher than in those from subcutaneous AT. Immunofluorescence staining revealed that YKL-40 was exclusively expressed in macrophages among SVF cells. YKL-40 purified from SVF cells inhibited the degradation of type I collagen, a major extracellular matrix of AT, by matrix metalloproteinase (MMP)-1 and increased rate of fibril formation of type I collagen. The expression of MMP-1 in preadipocytes and macrophages was enhanced by interaction between these cells. These results suggest that macrophage/preadipocyte interaction enhances degradation of type I collagen in AT, meanwhile, YKL-40 secreted from macrophages infiltrating into AT inhibits the type I collagen degradation.
Masahito Nakataki, Shusuke Numata, Junichi Iga, Shin'ya Tayoshi, Sumiko Tayoshi-Shibuya, Hongwei Song, Toshihito Tanahashi, Mitsuo Itakura, Shu-ichi Ueno and Tetsuro Ohmori : No association between Rho-associated coiled-coil forming protein serine/threonine kinase1 gene and schizophrenia in the Japanese population., Psychiatric Genetics, Vol.19, No.3, 162, 2009.
Shusuke Numata, Junichi Iga, Masahito Nakataki, Shinya Tayoshi, Kyoko Taniguchi, Satsuki Sumitani, Masahito Tomotake, Toshihito Tanahashi, Mitsuo Itakura, Yoko Kamegaya, Masahiko Tsutsumi, Akira Sano, Takashi Asada, Hiroshi Kunugi, Shu-ichi Ueno and Tetsuro Ohmori : Gene expression and association analyses of the phosphodiesterase 4B (PDE4B) gene in major depressive disorder in the Japanese population., American Journal of Medical Genetics. Part B, Neuropsychiatric Genetics, Vol.150B, No.4, 527-534, 2009.
(要約)
The phosphodiesterase 4B (PDE4B) interacts with disrupted-in-schizophrenia 1 (DISC1), which is a known genetic risk factor for schizophrenia, bipolar disorder and major depressive disorder (MDD). PDE4B is also important in the regulation of cAMP signaling, a second messenger implicated in learning, memory, and mood. In this study, we determined mRNA expression levels of the PDE4B gene in the peripheral blood leukocytes of patients with MDD and control subjects (n = 33, each). Next we performed two-stage case-controlled association analyses (first set; case = 174, controls = 348; second set; case = 481, controls = 812) in the Japanese population to determine if the PDE4B gene is implicated in MDD. In the leukocytes, a significantly higher expression of the PDE4B mRNA was observed in the drug-naïve MDD patients compared with control subjects (P < 0.0001) and the expression of the MDD patients significantly decreased after antidepressant treatment (P = 0.030). In the association analysis, we observed significant allelic associations of four SNPs (the most significant, rs472952; P = 0.002) and a significant haplotypic association (permutation P = 0.019) between the PDE4B gene and MDD in the first-set samples. However, we could not confirm these significant associations in the following independent second-set of samples. Our results suggest that the PDE4B gene itself does not link to MDD but the elevated mRNA levels of PDE4B might be implicated in the pathophysiology of MDD.
(キーワード)
Adult / Aged / Alleles / Case-Control Studies / Cyclic Nucleotide Phosphodiesterases, Type 4 / Depressive Disorder, Major / Female / Gene Expression / Gene Frequency / Genetic Predisposition to Disease / Genotype / Haplotypes / Humans / Japan / Male / Middle Aged / RNA, Messenger
Shusuke Numata, Junichi Iga, Masahito Nakataki, Shinya Tayoshi, Toshihito Tanahashi, Mitsuo Itakura, Shu-ichi Ueno and Tetsuro Ohmori : Positive association of the pericentrin (PCNT) gene with major depressive disorder in the Japanese population., Journal of Psychiatry & Neuroscience, Vol.34, No.3, 195-198, 2009.
(要約)
BACKGROUND: Pericentrin (PCNT) interacts with disruption-in-schizophrenia 1 (DISC1), a known genetic risk factor for schizophrenia, bipolar disorder and major depressive disorder (MDD). We sought to determine whether the PCNT gene is implicated in MDD. METHODS: We performed case-control association analyses in the Japanese population. We analyzed 9 single nucleotide polymorphisms (SNPs) in 173 patients with MDD and 348 healthy controls. RESULTS: We found a significant allelic association between 3 SNPs (rs3788265, rs2073376 and rs2073380) of the PCNT gene and MDD (p = 0.006, 0.005 and 0.021, respectively). After correction for multiple testing, 2 SNPs (rs3788265 and rs2073376) retained significant allelic associations with MDD. In addition, we found a significant association between the 2 marker haplotypes (r3788265 and rs2073376) and MDD (permutation p = 0.011). LIMITATIONS: Our sample was small and comprised only Japanese participants. In addition, owing to the late onset of MDD, it is possible that the disorder will develop in at least some participants in our control group. Finally, we did not show how SNPs of the PCNT gene alter its function. CONCLUSION: Our results suggest that genetic variations in the PCNT gene may play a significant role in the etiology of MDD in the Japanese population.
(文献検索サイトへのリンク)
● PubMed @ National Institutes of Health, US National Library of Medicine (PMID): 19448849
Kazumasa Nishimoto, Yuta Kochi, Katsunori Ikari, Kazuhiko Yamamoto, Akari Suzuki, Kenichi Shimane, Yusuke Nakamura, Koichiro Yano, Noriko Iikuni, So Tsukahara, Naoyuki Kamatani, Hiroshi Okamoto, Hirotaka Kaneko, Yasushi Kawaguchi, Masako Hara, Yoshiaki Toyama, Takahiko Horiuchi, Kayoko Tao, Koji Yasutomo, Daisuke Hamada, Natsuo Yasui, Hiroshi Inoue, Mitsuo Itakura, Hisashi Yamanaka and Shigeki Momohara : Association study of TRAF1-C5 polymorphisms with susceptibility to rheumatoid arthritis and systemic lupus erythematosus in Japanese., Annals of the Rheumatic Diseases, Vol.69, No.2, 368-373, 2009.
(要約)
The primary aim of this study was to investigate the association of polymorphisms of TRAF1-C5, a newly identified rheumatoid arthritis (RA) risk locus in Caucasians, with susceptibility to RA and systemic lupus erythematosus (SLE) in Japanese populations. Gene expression levels of TRAF1 and C5 to assess the functional significance of genotypes were also analysed. A multicentre association study consisting of 4 RA case-control series (4397 cases and 2857 controls) and 3 SLE case-control series (591 cases and 2199 shared controls) was conducted. Genotyping was performed using TaqMan genotyping assay for two single nucleotide polymorphisms (SNPs) that showed the best evidence of association in the previous Caucasian studies. Quantifications of TRAF1 and C5 expression were performed with TaqMan expression assay. Significant differences in allele frequency for both SNPs were observed between RA and control subjects (combined odds ratio = 1.09), while no significant difference was detected between patients with SLE and controls. Interestingly, alleles rs3761847 A and rs10818488 G had increased the risk for RA in the present study, while they decreased the risk in the original studies. A significant difference was found between risk allele carriers and non-carriers of rs10818488 for the expression level of TRAF1 in phorbol myristate acetate-stimulated lymphoblastoid cell lines (p = 0.04). Association of TRAF1-C5 locus with RA susceptibility was detected in the Japanese populations with modest magnitude, while no significant association was observed for SLE. Significant positive effect of genotype on the expression of TRAF1 might support the genetic association between TRAF1 and RA.
(キーワード)
Arthritis, Rheumatoid / Asian Continental Ancestry Group / Autoantibodies / Case-Control Studies / Cell Line / Complement C5 / Female / Genetic Predisposition to Disease / Genome-Wide Association Study / Genotype / Hand Joints / Humans / Lupus Erythematosus, Systemic / Male / Middle Aged / Polymorphism, Single Nucleotide / TNF Receptor-Associated Factor 1
Susumu Otsuka, Yumiko Sakamoto, Haruhiko Siomi, Mitsuo Itakura, Kenji Yamamoto, Hideo Matumoto, Tsukasa Sasaki, Nobumasa Kato and Eiji Nanba : Fragile X carrier screening and FMR1 allele distribution in the Japanese population., Brain & Development, Vol.32, No.2, 110-114, 2009.
(要約)
Fragile X syndrome (FXS), which is the most common form of familial mental retardation, is caused by the expansion of the CGG repeat in the FMR1 gene on the X chromosome. Previous studies have suggested that as compared to other populations, Japanese have a lower prevalence of FXS. In addition, in the normal population, there are no carriers who have the premutation allele. We analyzed a total of 946 normal Japanese (576 males and 370 females) and attempted to estimate the frequency of the FMR1 allele. Within this population, we found that 1,155 alleles were in the normal range (less than 40 CGG repeats) and had a modal number of 27 repeats (35.75%). No carriers with premutations (55-200 CGG repeats) were observed in this normal population. We also identified six intermediate-sized alleles (40-54 CGG repeats), with a reported incidence of 1 in 103 males and 1 in 324 females. However, this allele frequency was different from that previously reported for the Japanese population. Since data from previous studies has suggested that FXS might possibly be associated with the genetic mechanism of autism, we also analyzed the length of the CGG repeats in 109 autistic patients. In all cases the CGG repeat numbers were within the normal range (16-36 repeats) and no individuals presented with expanded premutation or intermediate alleles. This finding indicates that the length of the CGG repeat within the FMR1 is unlikely to be responsible for autism in Japanese.
(キーワード)
Asian Continental Ancestry Group / Autistic Disorder / Female / Fragile X Mental Retardation Protein / Fragile X Syndrome / Gene Frequency / Genetic Testing / Heterozygote / Humans / Male / Trinucleotide Repeat Expansion
Zhi-Rong Qian, Sylvia L Asa, Haruhiko Siomi, Mikiko Siomi, Katsuhiko Yoshimoto, Shozo Yamada, Elaine Lu Wang, Md Mustafizur Rahman, Hiroshi Inoue, Mitsuo Itakura, Eiji Kudo and Toshiaki Sano : Overexpression of HMGA2 relates to reduction of the let-7 and its relationship to clinicopathological features in pituitary adenomas., Modern Pathology, Vol.22, No.3, 431-441, 2009.
(要約)
High-mobility group A2 is highly expressed during embryogenesis and in various benign and malignant tumors. Recent studies report that high-mobility group A2 is negatively regulated by the let-7 microRNAs (miRNAs) family in vitro. The development of pituitary adenomas in high-mobility group A2 transgenic mice showed that high-mobility group A2 may be involved in pituitary tumorigenesis. However, no studies have investigated the clinical significance of high-mobility group A2 and its relationship to the let-7 miRNA family in human pituitary adenomas. Using immunohistochemistry, we analyzed high-mobility group A2 expression with respect to various clinicopathologic factors in 98 pituitary adenomas. Overexpression of high-mobility group A2 was observed in 39% (38/98) of pituitary adenomas compared with normal adenohypophysial tissue and was frequently found in adenomas including prolactin (PRL), adrenocorticotrophic hormone, or follicle-stimulating hormone/luteinizing hormone and in null cell adenomas, but relatively rare in growth hormone (GH) and mixed GH/PRL adenomas. High-mobility group A2 expression was significantly associated with tumor invasion (P<0.05) and was significantly higher in grade IV than in grades I, II, and III adenomas (P<0.05). High levels of high-mobility group A2 expression were more frequently observed in macroadenomas than in microadenomas (P<0.05). High levels of high-mobility group A2 expression also significantly correlated with the proliferation marker Ki-67 (P<0.0001). Real-time quantitative RT-PCR analysis was carried out to evaluate the expression of let-7 in 55 pituitary adenomas. Subsequently, decreased expression of let-7 was confirmed in 23 of 55 (42%) adenomas and was correlated with high-grade tumors (P<0.05). An inverse correlation between let-7 and high-mobility group A2 expression was evident (R=-0.33, P<0.05). These findings support a causal link between let-7 and high-mobility group A2 whereby loss of let-7 expression induces high-mobility group A2 upregulation that represents an important mechanism in pituitary tumorigenesis and progression.
Kiyoshi Kunika, Toshihito Tanahashi, Shusuke Numata, Shu-ichi Ueno, Tetsuro Ohmori, Naoto Nakamura, Kazue Tsugawa, Katsuyuki Miyawaki, Maki Moritani, Hiroshi Inoue and Mitsuo Itakura : Common coding variant in the TCF7L2 gene and study of the association with type 2 diabetes in Japanese subjects, Journal of Human Genetics, Vol.53, No.11-12, 972-982, 2008.
(要約)
Genetic variants of the transcription factor 7-like 2 (TCF7L2) gene affect the risk of type 2 diabetes in populations with multiple ethnic groups. However, a comprehensive survey of this gene has not been done for a Japanese population. Thus, we conducted this gene-based association study, in which the common genetic variants were analyzed. Using 24 Japanese type 2 diabetic subjects, we first screened a 9.5 kb region, which included the entire coding sequence, to assess potential functional variants of TCF7L2. Sequencing revealed a common coding variant (Pro477Thr) in exon 14 of TCF7L2 that was not enrolled in the public SNP database. Nineteen SNPs and the microsatellite DG10S478 were genotyped across the gene in 2,877 unrelated Japanese subjects. This independent screen identified the previously reported rs7903146 with a strongest association (allele P = 0.0001, odds ratio = 1.59 [95% confidence interval 1.25-2.01]), but there was no significant association between Pro477Thr and type 2 diabetes (allele P = 0.64). Expression of the Pro477Thr variant did not alter TCF7L2 expression in 30 lymphoblast cells. Although a genotypic effect of Pro477Thr on expression of TCF7L2 was not apparent, Pro477Thr was identified as a common variant of TCF7L2 in 2,877 Japanese subjects. Further functional studies are required to determine the possible effect of this coding variant on type 2 diabetes.
Kensuke Kondoh, Yuji Nakata, Takashi Yamaoka, Mitsuo Itakura, Mutsumi Hayashi, Kohji Yamada, Jun-ichi Hata and Taketo Yamada : Altered cellular immunity in transgenic mice with T cell-specific expression of human D4-guanine diphosphate-dissociation inhibitor (D4-GDI)., International Immunology, Vol.20, No.10, 1299-1311, 2008.
(要約)
D4-GDI, a Rho guanosine diphosphate (GDP) dissociation inhibitor, is preferentially expressed in hematopoietic tissues and binds to a small GTP-binding protein, Rho, and inhibits GDP dissociation from Rho. We identified point mutations in the D4-GDI gene in human leukemic cells. We therefore investigated the functions of D4-GDI and mutated D4-GDI in T cells. Transgenic mice (Tg) harboring human wild-type and mutant D4-GDI transgenes driven by the lck promoter were generated. Cellular immunity responses against cytozoic pathogens were examined. The cytoskeletal organization in the CD3+T cells and the proliferation of splenocytes by Con A were investigated in both Tg and littermates (LMs). Granuloma formation by bacille Calmette-Guerin was impaired in the wild-type D4-GDI Tg. On the other hand, the number of granulomas of the mutated D4-Tg was significantly higher. Infection with Listeria was more rapidly fatal to wild-type D4-GDI Tg than to LMs, while the survival of mutated D4-GDI Tg was prolonged. The CD3+T cells in wild-type D4-GDI Tg showed an impairment in the formation of stress fibers on anti-CD3 antibody-coated plates, whereas the cytoskeletal organization in CD3+T cells of the mutated D4-GDI Tg was augmented. The proliferation of splenocytes after Con A stimulation was higher in the mutated D4-GDI Tg than in the LMs. D4-GDI may have important functions, such as induction of T cell migration, adhesion and/or proliferation in inflammatory foci, in cellular immunity responses to cytozoic pathogens.
Katsuyuki Miyawaki, Hiroshi Inoue, Parvaneh Keshavarz, Kuniko Mizuta, Aya Sato, Yukiko Yamashita, Maki Moritani, Kiyoshi Kunika, Toshihito Tanahashi and Mitsuo Itakura : Transgenic expression of a mutated cyclin-dependent kinase 4 (CDK4/R24C) in pancreatic beta-cells prevents progression of diabetes in db/db mice., Diabetes Research and Clinical Practice, Vol.82, No.1, 33-41, 2008.
(要約)
In an attempt to rectify the hyperglycemic state in obese insulin resistant db/db mice, a transgenic line was generated (db/db-CDK4(R24C)) that expresses a constitutively active form of cyclin-dependent kinase 4 (CDK4/R24C) under the control of the insulin promoter. Compared with non-transgenic db/db littermates, adult db/db-CDK4(R24C) mice show near-complete glycemic normalization and improved plasma lipid concentrations, but are also more susceptible to weight gain and have significantly lower plasma adiponection levels. They have striking islet hypertrophy and beta-cell hyperplasia, and retain an insulin secretory response during the glucose tolerance test. We examined the expression of several key regulatory transcription factor genes involved in lipid and glucose metabolism in insulin target tissues of db/db-CDK4(R24C) as well as db/db mice, and found that the expression levels of members of the peroxisome proliferator-activated receptor (PPAR) family are highly associated with metabolic alterations in a gene- and tissue-specific manner. We show for the first time that the Ppar-delta in skeletal muscle and white adipose tissues is transcriptionally down-regulated in db/db mice. The db/db-CDK4(R24C) mice present a novel model of leptin-resistant obesity with compensatory hyperinsulinemia and normalized blood glucose levels, and thus may be useful for future studies that aim to dissect relationships between insulin and leptin signaling.
Kazuki Yasuda, Kazuaki Miyake, Yukiko Horikawa, Kazuo Hara, Haruhiko Osawa, Hiroto Furuta, Yushi Hirota, Hiroyuki Mori, Anna Jonsson, Yoshifumi Sato, Kazuya Yamagata, Yoshinori Hinokio, He-Yao Wang, Toshihito Tanahashi, Naoto Nakamura, Yoshitomo Oka, Naoko Iwasaki, Yasuhiko Iwamoto, Yuichiro Yamada, Yutaka Seino, Hiroshi Maegawa, Atsunori Kashiwagi, Jun Takeda, Eiichi Maeda, Hyoung Doo Shin, young Min Cho, Kyong Soo Park, Hong Kyu Lee, Maggie C Y Ng, Ronald C W Ma, Wing-Yee So, Juliana C N Chan, Valeriya Lyssenko, Tiinamaija Tuomi, Peter Nilsson, Leif Groop, Naoyuki Kamatani, Akihiro Sekine, Yusuke Nakamura, Ken Yamamoto, Teruhiko Yoshida, Katsushi Tokunaga, Mitsuo Itakura, Hideichi Makino, Kishio Nanjo, Takashi Kadowaki and Masato Kasuga : Variants in KCNQ1 are associated with susceptibility to type 2 diabetes mellitus., Nature Genetics, Vol.40, No.9, 1092-1097, 2008.
(要約)
We carried out a multistage genome-wide association study of type 2 diabetes mellitus in Japanese individuals, with a total of 1,612 cases and 1,424 controls and 100,000 SNPs. The most significant association was obtained with SNPs in KCNQ1, and dense mapping within the gene revealed that rs2237892 in intron 15 showed the lowest Pvalue (6.7 x 10(-13), odds ratio (OR) = 1.49). The association of KCNQ1 with type 2 diabetes was replicated in populations of Korean, Chinese and European ancestry as well as in two independent Japanese populations, and meta-analysis with a total of 19,930 individuals (9,569 cases and 10,361 controls) yielded a P value of 1.7 x 10(-42) (OR = 1.40; 95% CI = 1.34-1.47) for rs2237892. Among control subjects, the risk allele of this polymorphism was associated with impairment of insulin secretion according to the homeostasis model assessment of beta-cell function or the corrected insulin response. Our data thus implicate KCNQ1 as a diabetes susceptibility gene in groups of different ancestries.
(キーワード)
Asian Continental Ancestry Group / Chromosome Mapping / Diabetes Mellitus, Type 2 / European Continental Ancestry Group / Genetic Predisposition to Disease / Genome-Wide Association Study / Humans / Insulin-Secreting Cells / KCNQ1 Potassium Channel / Polymorphism, Single Nucleotide
Shu Kobayashi, Katsunori Ikari, Hirotaka Kaneko, Yuta Kochi, Kazuhiko Yamamoto, Kenichi Shimane, Yusuke Nakamura, Yoshiaki Toyama, Takeshi Mochizuki, So Tsukahara, Yasushi Kawaguchi, Chihiro Terai, Masako Hara, Taisuke Tomatsu, Hisashi Yamanaka, Takahiko Horiuchi, Kayoko Tao, Koji Yasutomo, Daisuke Hamada, Natsuo Yasui, Hiroshi Inoue, Mitsuo Itakura, Hiroshi Okamoto, Naoyuki Kamatani and Shigeki Momohara : Association of STAT4 with susceptibility to rheumatoid arthritis and systemic lupus erythematosus in the Japanese population., Arthritis and Rheumatism, Vol.58, No.7, 1940-1946, 2008.
(要約)
OBJECTIVE: STAT4 encodes a transcriptional factor that transmits signals induced by several key cytokines, and it might be a key molecule in the development of autoimmune diseases. Recently, a STAT4 haplotype was reported to be associated with rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE) in Caucasian populations. This was replicated in a Korean RA population. Interestingly, the degree of risk of RA susceptibility with the STAT4 haplotype was similar in the Caucasian and Korean populations. The present study was undertaken to investigate the effect of STAT4 on susceptibility to RA and SLE in the Japanese. METHODS: We performed an association study using 3 independent Japanese RA case-control populations (total 3,567 cases and 2,199 controls) and 3 independent Japanese SLE populations (total 591 cases). All samples were genotyped using the TaqMan fluorogenic 5' nuclease assay for single-nucleotide polymorphism (SNP) rs7574865, which tags the susceptibility haplotype. The association of the SNP with disease susceptibility in each case-control study was calculated using Fisher's exact test, and the results were combined, using the Mantel-Haenszel method, to obtain combined odds ratios (ORs). RESULTS: We observed a significant association of the STAT4 polymorphism with susceptibility to both RA and SLE. The combined ORs for RA and SLE, respectively, were 1.27 (P = 8.4 x 10(-9)) and 1.61 (P = 2.1 x 10(-11)) for allele frequency distribution; these ORs were quite similar to those previously observed in the Caucasian population. CONCLUSION: We conclude that STAT4 is associated with RA and SLE in the Japanese. Our results indicate that STAT4 is a common genetic risk factor for autoimmune diseases, with similar strength across major racial groups.
(キーワード)
Aged / Arthritis, Rheumatoid / Case-Control Studies / Female / Genetic Predisposition to Disease / Haplotypes / Humans / Japan / Lupus Erythematosus, Systemic / Male / Middle Aged / Polymorphism, Single Nucleotide / Risk Factors / STAT4 Transcription Factor
Yuka Nagasaki, Maki Moritani, Toshihito Tanahashi, Dai Osabe, Kyoko Nomura, Yuka Fujita, Parvaneh Keshavarz, Kiyoshi Kunika, Naoto Nakamura, Toshikazu Yoshikawa, Eiichiro Ichiishi, Hiroshi Shiota, Natsuo Yasui, Hiroshi Inoue and Mitsuo Itakura : Lack of association of genetic variation in chromosome region 15q14-22.1 with type 2 diabetes in a Japanese population., BMC Medical Genetics, Vol.9, 22, 2008.
(要約)
BACKGROUND: Chromosome 15q14-22.1 has been linked to type 2 diabetes (T2D) and its related traits in Japanese and other populations. The presence of T2D disease susceptibility variant(s) was assessed in the 21.8 Mb region between D15S118 and D15S117 in a Japanese population using a region-wide case-control association test. METHODS: A two-stage association test was performed using Japanese subjects: The discovery panel (Stage 1) used 372 cases and 360 controls, while an independent replication panel (Stage 2) used 532 cases and 530 controls. A total of 1,317 evenly-spaced, common SNP markers with minor allele frequencies > 0.10 were typed for each stage. Captured genetic variation was examined in HapMap JPT SNPs, and a haplotype-based association test was performed. RESULTS: SNP2140 (rs2412747) (C/T) in intron 33 of the ubiquitin protein ligase E3 component n-recognin 1 (UBR1) gene was selected as a landmark SNP based on repeated significant associations in Stage 1 and Stage 2. However, the marginal p value (p = 0.0043 in the allelic test, OR = 1.26, 95% CI = 1.07-1.48 for combined samples) was weak in a single locus or haplotype-based association test. We failed to find any significant SNPs after correcting for multiple testing. CONCLUSION: The two-stage association test did not reveal a strong association between T2D and any common variants on chromosome 15q14-22.1 in 1,794 Japanese subjects. A further association test with a larger sample size and denser SNP markers is required to confirm these observations.
Shusuke Numata, Shu-ichi Ueno, Junichi Iga, Hongwei Song, Masahito Nakataki, Shinya Tayoshi, Satsuki Sumitani, Masahito Tomotake, Mitsuo Itakura, Akira Sano and Tetsuro Ohmori : Positive association of the PDE4B (phosphodiesterase 4B) gene with schizophrenia in the Japanese population., Journal of Psychiatric Research, Vol.43, No.1, 7-12, 2008.
(要約)
The phosphodiesterase 4B (PDE4B) gene is located at 1p31, a susceptibility region for schizophrenia (SZ). Moreover, PDE4B interacts with DISC1, which is a known genetic risk factor for SZ. Recently, it was reported that the PDE4B gene is associated with SZ in Caucasian and African American populations. In this study, case-controlled association analyses were performed in the Japanese population to determine if the PDE4B gene is implicated in SZ. Thirteen single nucleotide polymorphisms (SNPs) were analyzed in 444 schizophrenic patients and 452 control subjects. Three SNPs (rs2180335, rs910694 and rs472952) were significantly associated with SZ after applying multiple test correction (p=0.039, 0.004 and 0.028). In addition, a significant association was found between specific haplotypes (rs2180335 and rs910694) and SZ (permutation p=0.001). Our result suggests that variations at the PDE4B locus may play a significant role in the etiology of SZ in the Japanese population.
(キーワード)
Asian Continental Ancestry Group / Case-Control Studies / Catechol O-Methyltransferase / Chromosome Mapping / Chromosomes, Human, Pair 1 / Control Groups / Cyclic Nucleotide Phosphodiesterases, Type 4 / Female / Gene Frequency / Genetic Markers / Genetic Predisposition to Disease / Genotype / Haplotypes / Humans / Linkage (Genetics) / Linkage Disequilibrium / Male / Middle Aged / Polymorphism, Single Nucleotide / Risk Factors / 統合失調症 (schizophrenia)
Shusuke Numata, Shu-ichi Ueno, Junichi Iga, Masahito Nakataki, Toshihito Tanahashi, Mitsuo Itakura, Akira Sano, Kazutaka Ohi, Ryota Hashimoto, Masatoshi Takada and Tetsuro Ohmori : No association between the NDE1 gene and schizophrenia in the Japanese population., Schizophrenia Research, Vol.99, No.1-3, 367-369, 2008.
(キーワード)
Adult / Aged / Alleles / Asian Continental Ancestry Group / Female / Gene Frequency / Genetic Predisposition to Disease / Genetics, Population / Genotype / Humans / Male / Microtubule-Associated Proteins / Middle Aged / Polymorphism, Single Nucleotide / 統合失調症 (schizophrenia)
Parvaneh Keshavarz, Hiroshi Inoue, Naoto Nakamura, Toshikazu Yoshikawa, Toshihito Tanahashi and Mitsuo Itakura : Single nucleotide polymorphisms in genes encoding LKB1 (STK11), TORC2 (CRTC2) and AMPK alpha2-subunit (PRKAA2) and risk of type 2 diabetes., Molecular Genetics and Metabolism, Vol.93, No.2, 200-209, 2008.
(要約)
The LKB1-AMPK-TORC2 signaling pathway controls glucose homeostasis in the liver, and mediates therapeutic effects of insulin-sensitizing antidiabetic agents. To examine whether genetic variations in genes encoding components of this signaling pathway contribute to increased susceptibility to type 2 diabetes, we screened STK11 (LKB1) and CRTC2 (TORC2) genes for genetic variants and conducted a case-control study in 1787 unrelated Japanese individuals. Additionally, the previously described association between the PRKAA2 (AMPK alpha2-subunit) haplotype and type 2 diabetes was tested for replication. We observed associations of nominal significance with two SNPs, an intronic SNP in the STK11 (rs741765; OR 1.33, 95% CI 1.05-1.67, p=0.017, under a recessive genetic model), and a non-synonymous SNP in the CRTC2 (6909C>T: Arg379Cys; OR 3.01, 95% CI 1.18-7.66, p=0.016, under a dominant model), although neither withstood correction for multiple testing. We were unable to replicate the association between the PRKAA2 haplotype and type 2 diabetes: however, in the single SNP evaluation, an intronic PRKAA2 SNP (rs1418442) that had previously been reported to be associated with serum cholesterol levels in Caucasian females showed a weak association (OR 0.62, 95% CI 0.40-0.96, p=0.030, under a recessive model). Among the three genes investigated herein, gene-gene (SNP-SNP) interaction studies provided evidence for an interaction between STK11 and CRTC2 influencing susceptibility to type 2 diabetes. Our findings suggest that genetic variants of LKB1-AMPK-TORC2 pathway components may exert a weak influence on the occurrence of type 2 diabetes in Japanese.
Toshihito Tanahashi, Keiko Shinohara, Parvaneh Keshavarz, Yuka Nagasaki, Katsuyuki Miyawaki, Kiyoshi Kunika, Maki Moritani, Naoto Nakamura, Toshikazu Yoshikawa, Hiroshi Shiota, Hiroshi Inoue and Mitsuo Itakura : The association of genetic variants in Krüppel-like factor 11 and Type 2 diabetes in the Japanese population., Diabetic Medicine, Vol.25, No.1, 19-26, 2008.
(要約)
Krüppel-like factor 11 (KLF11) is a transcriptional factor of the zinc finger domain family that regulates the expression of insulin. In North European populations, its common functional variant Q62R (rs35927125) is a strong genetic factor for Type 2 diabetes (P = 0.00033, odds ratio for G allele = 1.29, 95% CI 1.12-1.49). We examined the contribution of KLF11 variants to the susceptibility to Type 2 diabetes in a Japanese population. By re-sequencing Japanese individuals (n = 24, partly 96), we screened all four exons, exon/intron boundaries and flanking regions of KLF11. Verified single nucleotide polymorphisms (SNPs) were genotyped in 731 initial samples (369 control and 362 case subjects). Subsequently, we tested for association in 1087 samples (524 control and 563 case subjects), which were collected in different districts of Japan from the initial samples. We identified eight variants, including a novel A/C variant on intron 3, but no mis-sense mutations. In an association study, we failed to find any significant result of SNPs (minor allele frequency 8.2-46.2%) after correcting for multiple testing. Similarly, no haplotypes were associated with Type 2 diabetes. It is notable that the G allele in rs35927125 was completely absent in 1818 Japanese individuals. Genetic variants in KLF11 are unlikely to have a major effect of Type 2 diabetes in the Japanese population, although they were significantly associated in North European populations. These observations might help to determine the role of KLF11 variants in Type 2 diabetes in different populations.
(キーワード)
Adult / 分散分析 (analysis of variance) / Asian Continental Ancestry Group / Cell Cycle Proteins / Diabetes Mellitus, Type 2 / 女性 (female) / Gene Frequency / Genetic Predisposition to Disease / Genotype / Humans / インスリン (insulin) / 日本 (Japan) / Linkage Disequilibrium / 男性 (male) / Middle Aged / Repressor Proteins
When the homozygous active form of porcine TGF-beta1 transgene (Tgf/Tgf) (under control of the rat glucagon promoter) is introduced into the nonobese diabetic mouse (NOD) genetic background, the mice develop endocrine and exocrine pancreatic hypoplasia, low serum insulin concentrations, and impaired glucose tolerance. To identify genetic modifiers of the diabetic phenotypes, we crossed hemizygous NOD-Tgf with DBA/2J mice (D2) or C3H/HeJ mice (C3H) and used the "transgenic mice" for quantitative trait loci (QTL) analysis. Genome-wide scans of F(2)-D Tgf/Tgf (D2 x NOD) and F(2)-C Tgf/Tgf (C3H x NOD), homozygous for the TGF-beta1 transgene, identified six statistically significant modifier QTLs: one QTL (Tdn1) in F(2)-D Tgf/Tgf, and five QTLs (Tcn1 to Tcn5) in F(2)-C Tgf/Tgf. Tdn1 (Chr 13, LOD = 4.39), and Tcn3 (Chr 2, LOD = 4.94) showed linkage to body weight at 8 weeks of age. Tcn2 (Chr 7, LOD = 4.38) and Tcn4 (Chr 14, LOD = 3.99 and 3.78) showed linkage to blood glucose (BG) concentrations in ipGTT at 30, 0, and 120 min, respectively. Tcn1 (Chr 1, LOD = 4.41) and Tcn5 (Chr 18, LOD = 4.99) showed linkage to serum insulin concentrations in ipGTT at 30 min. Tcn2 includes the candidate gene, uncoupling protein 2 (Ucp2), and shows linkage to Ucp2 mRNA levels in the soleus muscle (LOD = 4.90). Identification of six QTLs for diabetes-related traits in F(2)-D Tgf/Tgf and F(2)-C Tgf/Tgf raises the possibility of identifying candidate susceptibility genes and new targets for drug development for human type 2 diabetes.
Yoichiro Takata, Hiroshi Inoue, Aya Sato, Kazue Tsugawa, Katsutoshi Miyatake, Daisuke Hamada, Fumio Shinomiya, Shunji Nakano, Natsuo Yasui, Toshihito Tanahashi and Mitsuo Itakura : Replication of reported genetic associations of PADI4, FCRL3, SLC22A4 and RUNX1 genes with rheumatoid arthritis: results of an independent Japanese population and evidence from meta-analysis of East Asian studies., Journal of Human Genetics, Vol.53, No.2, 163-173, 2008.
(要約)
We conducted population-based association tests for the four selected SNPs (rs2240340/padi4_94, rs7528684/fcrl3_3, rs3792876/slc2F2 and rs2268277/runx1) previously reported to be associated with rheumatoid arthritis (RA). The study population consisted of 950 unrelated Japanese subjects with RA and 507 controls, none of whom had previously been tested for these variants. Only the SNP rs2240340/padi4_94 was modestly associated with RA [allele odds ratio (OR) 1.22, 95% confidence interval (CI) 1.04-1.43, P=0.012]. The most significant association effect was found for genotype contrast between minor and major allele homozygotes (OR 1.53, 95% CI 1.10-2.12, P=0.010). No other SNPs showed a statistically significant association with RA in our population. Meta-analysis of published studies and our new data confirmed a highly significant association between PADI4 gene SNPs and increased risk of RA in East Asian populations (allele fixed-effects summary OR 1.31, 95% CI 1.22-1.41, P<0.0001). We found some evidence for an association of either rs7528684/fcrl3_3 or rs3792876/slc2F2 with RA; however, because the magnitudes of effects were apparently much weaker than those reported in the initial positive reports, and there were substantial levels of inter-study OR heterogeneity, we concluded that additional studies are needed to fully understand the present results.
Hiroko Hagiwara, Kazumi Sawakami-Kobayashi, Midori Yamamoto, Shoji Iwasaki, Mika Sugiura, Hatsumi Abe, Sumiko Kunihiro-Ohashi, Kumiko Takase, Noriko Yamane, Kaoru Kato, Renkon Son, Michihiro Nakamura, Osamu Segawa, Mamiko Yoshida, Masafumi Yohda, Hideji Tajima, Masato Kobori, Yousuke Takahama, Mitsuo Itakura and Masayuki Machida : Development of an automated SNP analysis method using a paramagnetic beads handling robot., Biotechnology and Bioengineering, Vol.98, No.2, 420-428, 2007.
(要約)
Biological and medical importance of the single nucleotide polymorphism (SNP) has led to development of a wide variety of methods for SNP typing. Aiming for establishing highly reliable and fully automated SNP typing, we have developed the adapter ligation method in combination with the paramagnetic beads handling technology, Magtration(R). The method utilizes sequence specific ligation between the fluorescently labeled adapter and the sample DNAs at the cohesive end produced by a type IIS restriction enzyme. Evaluation of the method using human genomic DNA showed clear discrimination of the three genotypes without ambiguity using the same reaction condition for any SNPs examined. The operations following PCR amplification were automatically performed by the Magtration(R)-based robot that we have previously developed. Multiplex typing of two SNPs in a single reaction by using four fluorescent dyes was successfully preformed at the almost same sensitivity and reliability as the single typing. These results demonstrate that the automated paramagnetic beads handling technology, Magtration(R), is highly adaptable to the automated SNP analysis and that our method best fits to an automated in-house SNP typing for laboratory and medical uses.
(キーワード)
Equipment Design / Genetic Testing / Genome, Human / Genotype / Humans / Magnetics / Polymerase Chain Reaction / Polymorphism, Single Nucleotide / Robotics / Sequence Analysis, DNA
Yukiko Yamashita, Hiroshi Inoue, Keshavarz Parvaneh, Katsuyuki Miyawaki, Yuka Nagasaki, Maki Moritani, Kiyoshi Kunika, Naoto Nakamura, Toshikazu Yoshikawa, Natsuo Yasui, Hiroshi Shiota, Toshihito Tanahashi and Mitsuo Itakura : SNPs in the KCNJ11-ABCC8 gene locus are associated with type 2 diabetes and blood pressure levels in the Japanese population., Journal of Human Genetics, Vol.52, No.10, 781-793, 2007.
(要約)
Many genetic association studies support a contribution of genetic variants in the KCNJ11-ABCC8 gene locus to type 2 diabetes (T2D) susceptibility in Caucasians. In non-Caucasian populations, however, there have been only a few association studies, and discordant results were obtained. Herein, we selected a total of 31 SNPs covering a 211.3-kb region of the KCNJ11-ABCC8 locus, characterized the patterns of linkage disequilibrium (LD) and haplotype structure, and performed a case-control association study in a Japanese population consisting of 909 T2D patients and 893 control subjects. We found significant associations between eight SNPs, including the KCNJ11 E23K and ABCC8 S1369A variants, and T2D. These disease-associated SNPs were genetically indistinguishable because of the presence of strong LD, as found previously in Caucasians. For the KCNJ11 E23K variant, the most significant association was obtained under a dominant genetic model (OR 1.32, 95% CI 1.09-1.60, P = 0.004). A meta-analysis of East Asian studies, comprising a total of 3,357 T2D patients (77.4% Japanese) and 2,836 control subjects (77.8% Japanese), confirmed the significant role of the KCNJ11 E23K variant in T2D susceptibility. Furthermore, we found evidence suggesting that the KCNJ11 E23K genotype is independently associated with higher blood-pressure levels.
(キーワード)
ATP-Binding Cassette Transporters / Aged / Asian Continental Ancestry Group / 血圧 (blood pressure) / Diabetes Mellitus, Type 2 / 女性 (female) / Humans / 日本 (Japan) / 男性 (male) / Middle Aged / Polymorphism, Single Nucleotide / Potassium Channels / Potassium Channels, Inwardly Rectifying / Receptors, Drug
S Yamasaki, N Kurita, J Hata, Maki Moritani, Mitsuo Itakura and Mitsuo Shimada : The effect of transgenic expression of TGF-beta1 on transplanted islet graft survival., Hepato-Gastroenterology, Vol.54, No.78, 1617-1621, 2007.
(要約)
Transgenic mice expressing the active form of porcine TGF-beta1 (NOD- TGF-beta1 Tg) were completely protected from autoimmune diabetes in the NOD genetic background in our previous study. Here, we attempted to determine whether transgenic expression of TGF-beta1 in transplanted islets prevents autoimmune destruction in NOD mice. We transplanted islets to the subcapsular region of the kidney using NOD-TGF-beta1 Tg and NOD mice as donor and recipient or vice versa. Cyclophosphamide was administered twice to streptozocin-induced diabetic females NOD-TGF-beta1 Tg or their female littermates after islet transplantation. All islets grafts of NOD-TGF-beta1 Tg in spontaneously diabetic NOD mice were rejected earlier than those of their littermates. Hyperglycemia was induced in all littermates, but three out of four NOD-TGF-beta1 Tg, which were STZ-induced diabetic female mice, remained normoglycemic in response to the administration of cyclophosphamide after islet transplantation. Our results lack direct evidence for the local paracrine TGF-beta1 to protect the transplanted islet grafts. We observed, however, prolonged survival of NOD islets grafts in diabetic NOD-TGF-beta1 Tg suggesting the protective role of transgenic TGF-beta1 to suppress the autoimmune process in our syngenic transplantation model. We are convinced that this data could help resolve many problems regarding islet transplantation for type 1 diabetes.
Katsutoshi Miyatake, Hiroshi Inoue, Kahoko Hashimoto, Hiroshi Takaku, Yoichiro Takata, Shunji Nakano, Natsuo Yasui and Mitsuo Itakura : PKC412 (CGP41251) modulates the proliferation and lipopolysaccharide-induced inflammatory responses of RAW 264.7 macrophages., Biochemical and Biophysical Research Communications, Vol.360, No.1, 115-121, 2007.
(要約)
PKC412 (CGP41251) is a multitarget protein kinase inhibitor with anti-tumor activities. Here, we investigated the effects of PKC412 on macrophages. PKC412 inhibited the proliferation of murine RAW 264.7 macrophages through induction of G2/M cell cycle arrest and apoptosis. At non-toxic drug concentrations, PKC412 significantly suppressed the lipopolysaccharide (LPS)-induced release of TNF-alpha and nitric oxide, while instead enhancing IL-6 secretion. PKC412 attenuated LPS-induced phosphorylations of MKK4 and JNK, as well as AP-1 DNA binding activities. Furthermore, PKC412 suppressed LPS-induced Akt and GSK-3beta phosphorylations. These results suggest that the anti-proliferative and immunomodulatory effects of PKC412 are, at least in part, mediated through its interference with the MKK4/JNK/AP-1 and/or Akt/GSK-3beta pathways. Since macrophages contribute significantly to the development of both acute and chronic inflammation, PKC412 may have therapeutic potential and applications in treating inflammatory and/or autoimmune diseases.
(キーワード)
Animals / アポトーシス (apoptosis) / Cell Line / Cell Proliferation / Cytokines / Dose-Response Relationship, Drug / Drug Combinations / Immunologic Factors / Lipopolysaccharides / Macrophages / Mice / Staurosporine
Masaaki Ochi, Haruhiko Osawa, Yushi Hirota, Kazuo Hara, Yasuharu Tabara, Yoshiharu Tokuyama, Ikki Shimizu, Azuma Kanatsuka, Yasuhisa Fujii, Jun Ohashi, Tetsuro Miki, Naoto Nakamura, Takashi Kadowaki, Mitsuo Itakura, Masato Kasuga and Hideichi Makino : The frequency of the G/G genotype of resistin single nucleotide polymorphism at -420 appears to be increased in younger onset type 2 diabetes., Diabetes, Vol.56, No.11, 2834-2838, 2007.
(要約)
Resistin is an adipocyte-secreted cytokine associated with insulin resistance in mice. We previously reported that the G/G genotype of a resistin single nucleotide polymorphism (SNP) at -420 increases type 2 diabetes susceptibility by enhancing its promoter activity. The aim of the present study was to determine the relevance of SNP -120 in a large number of subjects. We examined 2,610 type 2 diabetic case and 2,502 control subjects. The relation between SNP -420 and the age of type 2 diabetes onset was further analyzed by adding 237 type 2 diabetic subjects with age of onset <or=40 years. When analyzed without considering subject age, the SNP -420 genotype was not associated with type 2 diabetes. Since we reported that the onset of type 2 diabetes was earlier in G/G genotype, we analyzed the data using a trend test for age intervals of 10 years. The frequency of G/G genotype differed among age grades in type 2 diabetes (P = 0.037) and appeared to be higher in younger grades. In type 2 diabetes, G/G genotype was more frequent in subjects aged <40 years than in those aged >or=40 years (G/G vs. C/C, P = 0.003). In a total of 2,430 type 2 diabetic subjects with age of onset <60 years, the trend test showed that the G/G genotype had an increasing linear trend as the age grade of type 2 diabetes onset became younger (P = 0.0379). In control subjects, the frequency of C/G genotype showed an increasing linear trend with increasing age (P = 0.010). The G/G genotype frequency of resistin SNP -420 appears to be increased in younger-onset type 2 diabetic subjects.
(キーワード)
Adult / Age of Onset / Animals / Diabetes Mellitus, Type 2 / Gene Frequency / Genotype / Guanine / Humans / Mice / Mice, Knockout / Middle Aged / Polymorphism, Single Nucleotide / Reference Values / Resistin
Dai Osabe, Toshihito Tanahashi, Kyoko Nomura, Shuichi Shinohara, Naoto Nakamura, Toshikazu Yoshikawa, Hiroshi Shiota, Parvaneh Keshavarz, Yuka Nagasaki, Kiyoshi Kunika, Maki Moritani, Hiroshi Inoue and Mitsuo Itakura : Evaluation of sample size effect on the identification of haplotype blocks., BMC Bioinformatics, Vol.8, 200, 2007.
(要約)
Genome-wide maps of linkage disequilibrium (LD) and haplotypes have been created for different populations. Substantial sharing of the boundaries and haplotypes among populations was observed, but haplotype variations have also been reported across populations. Conflicting observations on the extent and distribution of haplotypes require careful examination. The mechanisms that shape haplotypes have not been fully explored, although the effect of sample size has been implicated. We present a close examination of the effect of sample size on haplotype blocks using an original computational simulation. A region spanning 19.31 Mb on chromosome 20q was genotyped for 1,147 SNPs in 725 Japanese subjects. One region of 445 kb exhibiting a single strong LD value (average |D'|; 0.94) was selected for the analysis of sample size effect on haplotype structure. Three different block definitions (recombination-based, LD-based, and diversity-based) were exploited to create simulations for block identification with theta value from real genotyping data. As a result, it was quite difficult to estimate a haplotype block for data with less than 200 samples. Attainment of a reliable haplotype structure with 50 samples was not possible, although the simulation was repeated 10,000 times. These analyses underscored the difficulties of estimating haplotype blocks. To acquire a reliable result, it would be necessary to increase sample size more than 725 and to repeat the simulation 3,000 times. Even in one genomic region showing a high LD value, the haplotype block might be fragile. We emphasize the importance of applying careful confidence measures when using the estimated haplotype structure in biomedical research.
Takeo Iwata, Noriko Mizusawa, Yutaka Taketani, Mitsuo Itakura and Katsuhiko Yoshimoto : Parafibromin tumor suppressor enhances cell growth in the cells expressing SV40 large T antigen., Oncogene, Vol.26, No.42, 6176-6183, 2007.
(要約)
Parafibromin (PF) is a 531-amino acid protein encoded by HRPT2, a putative tumor suppressor gene recently implicated in the autosomal-dominant hyperparathyroidism-jaw tumor familial cancer syndrome and sporadic parathyroid carcinoma. To investigate effects of PF's overexpression on cell proliferation, we performed assays in four different cell lines. The transient overexpression of PF inhibited cell growth in HEK293 and NIH3T3 cells, but enhanced cell growth in the SV40 large T antigen-expressing cell lines such as 293FT and COS7 cells. In 293FT cells, PF was found to interact with SV40 large T antigen and its overexpression promoted entry into the S phase, implying that the interaction enhanced progression through the cell cycle. The tumor suppressor protein PF acts as a positive regulator of cell growth similar to an oncoprotein in the presence of SV40 large T antigen.
Atsushi Inouchi, Shuichi Shinohara, Hiroshi Inoue, Kenji Kita and Mitsuo Itakura : Identification of specific sequence motifs in the upstream region of 242 human miRNA genes., Computational Biology and Chemistry, Vol.31, No.3, 207-214, 2007.
Kuniko Mizuta, Satoshi Tsutsumi, Hiroshi Inoue, Yukiko Yamashita, Katsutoshi Miyatake, Katsuyuki Miyawaki, Sumihare Noji, Nobuyuki Kamata and Mitsuo Itakura : Molecular characterization of GDD1/TMEM16E, the gene product responsible for autosomal dominant gnathodiaphyseal dysplasia., Biochemical and Biophysical Research Communications, Vol.357, No.1, 126-132, 2007.
(要約)
The human GDD1/TMEM16E gene has been found to be mutated in gnathodiaphyseal dysplasia, an unusual skeletal syndrome with autosomal dominant inheritance. The molecular and biochemical function(s) of GDD1 protein has not yet been elucidated. In this study, we examined the murine GDD1 gene expression pattern during embryonic development, and characterized the cellular and tissue localizations of its gene product using a GDD1-specific antibody. In the developing embryos, GDD1 mRNA expression was principally associated with differentiating and developing somites, with a highly complex spatiotemporal pattern that involved the myotomal and sclerotomal lineages of somites. Biochemical studies indicated that GDD1 protein is an integral membrane glycoprotein that resides predominantly in intracellular vesicles. Immunohistochemical analysis showed a high level of murine GDD1 protein expression in cardiac and skeletal muscle tissues, and in growth-plate chondrocytes and osteoblasts in bone. These observations suggest diverse cellular role(s) of GDD1 in the development of musculoskeletal system.
(キーワード)
Animals / Bone Diseases / Chromosome Disorders / Embryonic Development / Genes, Dominant / Membrane Proteins / Mice / Muscle, Skeletal / 心筋 (myocardium) / Organ Specificity / Tissue Distribution
Yoichiro Takata, Daisuke Hamada, Katsutoshi Miyatake, Shunji Nakano, Fumio Shinomiya, Charles R. Scafe, Vincent M. Reeve, Dai Osabe, Maki Moritani, Kiyoshi Kunika, Naoyuki Kamatani, Hiroshi Inoue, Natsuo Yasui and Mitsuo Itakura : Genetic association between the PRKCH gene encoding protein kinase Ceta isozyme and rheumatoid arthritis in the Japanese population., Arthritis and Rheumatism, Vol.56, No.1, 30-42, 2007.
(要約)
Analyses of families with rheumatoid arthritis (RA) have suggested the presence of a putative susceptibility locus on chromosome 14q21-23. This large population-based genetic association study was undertaken to examine this region. A 2-stage case-control association study of 950 unrelated Japanese patients with RA and 950 healthy controls was performed using >400 gene-based common single-nucleotide polymorphisms (SNPs). Multiple SNPs in the PRKCH gene encoding the eta isozyme of protein kinase C (PKCeta) showed significant single-locus disease associations, the most significant being SNP c.427+8134C>T (odds ratio 0.72, 95% confidence interval 0.62-0.83, P = 5.9 x 10(-5)). Each RA-associated SNP was consistently mapped to 3 distinct regions of strong linkage disequilibrium (i.e., linkage disequilibrium or haplotype blocks) in the PRKCH gene locus, suggesting that multiple causal variants influence disease susceptibility. Significant SNPs included a novel common missense polymorphism of the PRKCH gene, V374I (rs2230500), which lies within the ATP-binding site that is highly conserved among PKC superfamily members. In circulating lymphocytes, PRKCH messenger RNA was expressed at higher levels in resting T cells (CD4(+) or CD8(+)) than in B cells (CD19(+)) or monocytes (CD14(+)) and was significantly down-regulated through immune responses. Our results provide evidence of the involvement of PRKCH as a susceptibility gene for RA in the Japanese population. Dysregulation of PKCeta signal transduction pathway(s) may confer increased risk of RA through aberrant T cell-mediated autoimmune responses.
(キーワード)
Adult / Arthritis, Rheumatoid / Case-Control Studies / Chromosomes, Human, Pair 14 / Female / Genetic Predisposition to Disease / Humans / Isoenzymes / Japan / Linkage Disequilibrium / Male / Middle Aged / Polymorphism, Single Nucleotide / Protein Kinase C / RNA, Messenger / Signal Transduction / T-Lymphocytes / Zebrafish Proteins
Maki Moritani, Kyoko Nomura, Toshihito Tanahashi, Dai Osabe, Yuka Fujita, Shinohara Syuichi, Yuka Nagasaki, Parvaneh Keshavarz, Eiji Kudo, Naoto Nakamura, Toshikazu Yoshikawa, Eiichiro Ichiichi, Yoichiro Takata, Natsuo Yasui, Hiroshi Shiota, Kiyoshi Kunika, Hiroshi Inoue and Mitsuo Itakura : Genetic association of single nucleotide polymorphisms in endonuclease G-like 1 gene with type 2 diabetes in a Japanese population., Diabetologia, Vol.50, No.6, 1218-1227, 2007.
(要約)
In order to identify type 2 diabetes disease susceptibility gene(s) in a Japanese population, we applied a region-wide case-control association test to the 20.4 Mb region between D3S1293 and D3S2319 on chromosome 3p24.3-22.1, supported by linkage to type 2 diabetes and its related traits in Japanese and multiple populations. We performed a two-stage association test using 1,762 Japanese persons with 485 gene-centric, evenly spaced, common single nucleotide polymorphism (SNP) markers with minor allele frequency >0.1. For mouse studies, total RNA was extracted from various organs of BKS.Cg-+Lepr(db)/+Lepr(db) and control mice, and from MIN6, NIH3T3 and C2C12 cell lines. We detected a landmark SNP375 (A/G) (rs2051211, p = 0.000046, odds ratio = 1.33, 95% CI 1.16-1.53) in intron 5 of the endonuclease G-like 1 (ENDOGL1) gene. Systematic dense SNPs approach identified a susceptibility linkage disequilibrium (LD) block of 116.5 kb by |D'|, an LD units map and a critical region of 2.1 kb by r (2) in ENDOGL1. A haplotype-based association test showed that an at-risk haplotype is associated with disease status (p = 0.00001). The expression of ENDOGL1 was rather ubiquitous with relatively abundant expression in the brain and also in a pancreatic islet beta cell line. Mouse Endogl1 expression increased in pancreatic islets of hyperglycaemic BKS.Cg-+Lepr(db)/+Lepr(db) mice compared with that in control mice. Based on the population genetics, fine mapping of LD block and haplotype analysis, we conclude that ENDOGL1 is a candidate disease-susceptibility gene for type 2 diabetes in a Japanese population. Further analysis in a larger sample size is required to substantiate this conclusion.
(キーワード)
Adult / Aged / Body Mass Index / Case-Control Studies / Diabetes Mellitus, Type 2 / Endodeoxyribonucleases / Endonucleases / Female / Genetic Predisposition to Disease / Hemoglobin A, Glycosylated / Humans / Japan / Male / Middle Aged / Polymorphism, Single Nucleotide / Reference Values
Yukiko Yamashita, Hiroshi Inoue, Shuhei Kawakami, Katsuyuki Miyawaki, Tatsuro Miyamoto, Kuniko Mizuta and Mitsuo Itakura : Expression and distribution of Gpr119 in the pancreatic islets of mice and rats: Predominant localization in pancreatic polypeptide-secreting PP-cells., Biochemical and Biophysical Research Communications, Vol.351, No.2, 474-480, 2006.
(要約)
The GPR119 was recently shown to be activated by oleoylethanolamide (OEA), a naturally occurring bioactive lipid with hypophagic and anti-obesity effects. In this study, we have cloned and characterized its murine counterpart, Gpr119. The full-length cDNA contained an open reading frame of 1008bp encoding a 335-amino acid protein. The genomic organization of Gpr119 was unique, having a 3'-untranslated second exon that was also involved in an alternative splicing event. Gene expression analyses confirmed its specific expressions in pancreatic islets and two endocrine cell-lines, MIN6 and alphaTC1. Immunohistochemistry and double-immunofluorescence studies using a specific antibody revealed the predominant Gpr119 localization in pancreatic polypeptide (PP)-cells of islets. No definitive evidence of Gpr119-immunoreactivity in adult beta- or alpha-cells was obtained. The Gpr119 mRNA levels were elevated in islets of obese hyperglycemic db/db mice as compared to control islets, suggesting a possible involvement of this receptor in the development of obesity and diabetes.
(キーワード)
3' Untranslated Regions / Alternative Splicing / Animals / Base Sequence / Cell Line / Cloning, Molecular / Exons / Hyperglycemia / Islets of Langerhans / Male / Mice / Mice, Obese / Molecular Sequence Data / Open Reading Frames / Pancreatic Polypeptide-Secreting Cells / RNA, Messenger / Rats / Receptors, G-Protein-Coupled / Recombinant Fusion Proteins
Kiyoshi Kunika, Toshihito Tanahashi, Eiji Kudo, Noriko Mizusawa, Eiichiro Ichiishi, Naoto Nakamura, Toshikazu Yoshikawa, Takashi Yamaoka, Hiroaki Yasumo, Kazue Tsugaw, Maki Moritani, Hiroshi Inoue and Mitsuo Itakura : Effect of +36T > C in intron 1 on the glutamine: fructose-6-phosphate amidotransferase 1 gene and its contribution to type 2 diabetes in different populations., Journal of Human Genetics, Vol.51, No.12, 1100-1109, 2006.
(要約)
Glutamine: fructose-6-phosphate amidotransferase 1 (GFPT1) acts as a rate-limiting enzyme in the hexosamine biosynthetic pathway, which is an alternative branch of glucose metabolism. To evaluate GFPT1 as a susceptibility gene to type 2 diabetes, we surveyed the polymorphisms related with the gene function of GFPT1 and assessed its contribution to type 2 diabetes with a case-control association study. Screening of the 5'-flanking and all coding regions of GFPT1 revealed eight polymorphisms, one in the 5'-flanking region, one synonymous polymorphism in exon 8, five in introns and one in 3'-UTR, but no mis-sense or non-sense polymorphism. With in silico simulation, a putative promoter region was apparently predicted between 1 kb upstream and 1 kb downstream of the start codon. In this region, +36T>C polymorphism was located on the GC box sequence in intron 1, and its functional effect on promoter activity was confirmed by luciferase reporter assay, introducing a new functional polymorphism of the GFPT1 gene. To examine its association with type 2 diabetes, we analyzed 2,763 Japanese (1,461 controls and 1,302 cases) and 330 Caucasians (190 controls and 140 cases). One possible association of +36T>C was observed in Caucasians, but no association of polymorphisms including +36T>C in intron 1 or haplotypes was observed in Japanese. Although we could not completely rule out a contribution to specific sub-groups or other populations, genetic variation of GFPT1 is unlikely to have a major role in the susceptibility to type 2 diabetes in Japanese.
(キーワード)
5' Flanking Region / Adult / Aged / Aged, 80 and over / Asian Continental Ancestry Group / Base Sequence / Case-Control Studies / Diabetes Mellitus, Type 2 / European Continental Ancestry Group / Female / Genetic Predisposition to Disease / Glutamine-Fructose-6-Phosphate Transaminase (Isomerizing) / Humans / Introns / Male / Middle Aged / Molecular Sequence Data / Polymorphism, Single Nucleotide / Promoter Regions, Genetic
Shigeru Takeshita, Maki Moritani, Kiyoshi Kunika, Hiroshi Inoue and Mitsuo Itakura : Diabetic modifier QTLs identified in F2 intercrosses between Akita and A/J mice., Mammalian Genome, Vol.17, No.9, 927-940, 2006.
(要約)
To identify novel genetic modifiers of type 2 diabetes (T2D), we performed quantitative trait loci (QTL) analysis on F(2) progeny of hypoinsulinemic diabetic Akita mice, heterozygous for the Ins2 gene Cys96Tyr mutation, and nondiabetic A/J mice. We generated 625 heterozygous (F(2)-Hetero) and 338 wild-type (F(2)-Wild) mice with regard to the Ins2 mutation in F(2) intercross progeny. We measured quantitative traits, including plasma glucose and insulin concentrations during the intraperitoneal glucose tolerance test (IPGTT), and body weight (BW). We observed three significant QTLs in hypoinsulinemic hyperglycemic male F(2)-Hetero mice, designated Dbm1, Dbm3, and Dbm4 on Chromosomes 6, 14, and 15, respectively. They showed linkage to plasma glucose concentrations, with significant maximum logarithm of odds (LOD) scores of 4.12, 4.17, and 6.17, respectively, all exceeding threshold values by permutation tests. In normoinsulinemic normoglycemic male F(2)-Wild mice, Dbm1 on Chromosome 6 showed linkage to both plasma insulin concentrations and BW, and Dbm2 on Chromosome 11 showed linkage to plasma glucose concentrations only, with LOD scores of 4.52 and 6.32, and 5.78, respectively. Based on these results, we concluded that Dbm1, Dbm2, Dbm3, and Dbm4 represent four major modifier QTLs specifically affecting T2D-related traits and that these diabetic modifier QTLs are conditional on the heterozygous Ins2 gene mutation and sex to exert their modifier functions. Identification of the genes responsible for these QTLs would provide new drug development targets for human T2D.
Toshihito Tanahashi, Dai Osabe, Kyoko Nomura, Syuichi Shinohara, Hitoshi Kato, Eiichiro Ichiishi, Naoto Nakamura, Toshikazu Yoshikawa, Yoichiro Takata, Tatsuro Miyamoto, Hiroshi Shiota, Parvaneh Keshavarz, Yuka Nagasaki, Kiyoshi Kunika, Maki Moritani, Hiroshi Inoue and Mitsuo Itakura : Association study on chromosome 20q11.21-13.13 locus and its contribution to type 2 diabetes susceptibility in Japanese., Human Genetics, Vol.120, No.4, 527-542, 2006.
(要約)
Several linkage studies have predicted that human chromosome 20q is closely related to type 2 diabetes, but there is no clear evidence that certain variant(s) or gene(s) have strong effects on the disease within this region. To examine disease susceptibility variant in Japanese, verified SNPs from the databases, with a minor allele frequency larger than 0.15, were selected at 10-kb intervals across a 19.31-Mb region (20q11.21-13.13), which contained 291 genes, including hepatocyte nuclear factor 4alpha (HNF4alpha). As a result, a total of 1,147 SNPs were genotyped with TaqMan assay using 1,818 Japanese samples. By searching for HNF4alpha as a representative disease-susceptible gene, no variants of HNF4alpha were strongly associated with disease. To identify other genetic variant related with disease, we designed an extensive two-stage association study (725 first and 1,093 second test samples). Although SNP1146 (rs220076) was selected as a landmark within the 19.31 Mb region, the magnitude of the nominal P value (P = 0.0023) was rather weak. Subsequently, a haplotype-based association study showed that two common haplotypes were weakly associated with disease. All of these tests resulted in non-significance after adjusting for Bonferroni's correction and the false discovery rate to control for the impact of multiple testing. Contrary to the initial expectations, we could not conclude that certain SNPs had a major effect on this promising locus within the framework presented here. As a way to extend our observations, we emphasize the importance of a subsequent association study including replication and/or meta-analysis in multiple populations.
(キーワード)
Aged / Asian Continental Ancestry Group / Chromosome Mapping / Chromosomes, Human, Pair 20 / Diabetes Mellitus, Type 2 / Female / Gene Frequency / Genetic Predisposition to Disease / Genotype / Haplotypes / Hepatocyte Nuclear Factor 4 / Humans / 日本 (Japan) / Linkage Disequilibrium / Lod Score / Male / Middle Aged / Polymorphism, Single Nucleotide
Maki Moritani, Katsuhiko Togawa, Hiroshi Yaguchi, Yuka Fujita, Yuka Nagasaki, Hiroshi Inoue, Naoyuki Kamatani and Mitsuo Itakura : Identification of diabetes susceptibility loci in db mice by combined quantitative trait loci analysis and haplotype mapping., Genomics, Vol.88, No.6, 719-730, 2006.
(要約)
To identify the disease-susceptibility genes of type 2 diabetes, we performed quantitative trait loci (QTL) analysis in F(2) populations generated from a BKS.Cg-m+/+Lepr(db) and C3H/HeJ intercross, taking advantage of genetically determined obesity and diabetes traits associated with the db gene. A genome-wide scan in the F(2) populations divided by sex and db genotypes identified 14 QTLs in total and 3 major QTLs on chromosome (Chr) 3 (LOD 5.78) for fat pad weight, Chr 15 (LOD 6.64) for body weight, and Chr 16 (LOD 8.15) for blood glucose concentrations. A linear-model-based genome scan using interactive covariates allowed us to consider sex- or sex-by db-specific effects of each locus. For the most significant QTL on Chr 16, the high-resolution haplotype comparison between BKS and C3H strains reduced the critical QTL interval from 20 to 4.6 Mb by excluding shared haplotype regions and identified 11 nonsynonymous single-nucleotide polymorphisms in six candidate genes.
Yoichiro Takata, Yoshito Matsui, Daisuke Hamada, Tomohiro Goto, Takahiro Kubo, Hiroshi Egawa, Shunji Nakano, Fumio Shinomiya, Hiroshi Inoue, Mitsuo Itakura and Natsuo Yasui : The alpha 2 type IX collagen gene tryptophan polymorphism is not associated with rheumatoid arthritis in the Japanese population, Clinical Rheumatology, Vol.25, No.4, 491-494, 2006.
(要約)
The aim of this study was to investigate whether the alpha 2 type IX collagen (COL9A2) polymorphism that introduces tryptophan residue into the collagen triple-helix is a marker of susceptibility to, or severity of, rheumatoid arthritis (RA). The study included 749 Japanese patients with RA. One hundred twenty-four unrelated healthy individuals served as the control subjects. The relationship between the COL9A2 gene polymorphism and clinical manifestations of RA was evaluated. For the number of subjects positive for COL9A2 tryptophan polymorphism, there was no statistically significant difference between RA patients and normal controls. Furthermore, we did not detect any association of COL9A2 tryptophan polymorphism with disease status, least erosive subset, more erosive subset, or mutilating disease. The lack of association of COL9A2 tryptophan polymorphism with RA and the clinical findings in our study implies that the polymorphism may not function as a candidate gene marker for screening RA patients.
(キーワード)
Polymorphism - Rheumatoid arthritis / Severity - Susceptibility / Type IX collagen
Hitoshi Kato, Kyoko Nomura, Dai Osabe, Shuichi Shinohara, Osamu Mizumori, Rumi Katashima, Shoji Iwasaki, Koichi Nishimura, Masayasu Yoshino, Masato Kobori, Eiichiro Ichiishi, Naoto Nakamura, Toshikazu Yoshikawa, Toshihito Tanahashi, Parvaneh Keshavarz, Kiyoshi Kunika, Maki Moritani, Eiji Kudo, Kazue Tsugawa, Yoichiro Takata, Daisuke Hamada, Natsuo Yasui, Tatsuro Miyamoto, Hiroshi Shiota, Hiroshi Inoue and Mitsuo Itakura : Association of single nucleotide polymorphisms in the suppressor of cytokine signaling 2 (SOCS2) gene with type 2 diabetes in the Japanese., Genomics, Vol.87, No.4, 446-458, 2006.
(要約)
Several previous linkage scans in type 2 diabetes (T2D) families indicated a putative susceptibility locus on chromosome 12q15-q22, while the underlying gene for T2D has not yet been identified. We performed a region-wide association analysis on 12q15-q22, using a dense set of >500 single-nucleotide polymorphisms (SNPs), in 1492 unrelated Japanese individuals enrolled in this study. We identified an association between T2D and a haplotype block spanning 13.6 kb of genomic DNA that includes the entire SOCS2 gene. Evolutionary-based haplotype analysis of haplotype-tagging SNPs followed by a "sliding window" haplotypic analysis indicated SNPs that mapped to the 5' region of the SOCS2gene to be associated with T2D with high statistical significance. The SOCS2 gene was expressed ubiquitously in human and murine tissues, including pancreatic beta-cell lines. Adenovirus-mediated expression of the SOCS2 gene in MIN6 cells or isolated rat islets significantly suppressed glucose-stimulated insulin secretion. Our data indicate that SOCS2 may play a role in susceptibility to T2D in the Japanese.
Parvaneh Keshavarz, Hiroshi Inoue, Yukiko Yamashita, Kiyoshi Kunika, Toshihito Tanahashi, Naoto Nakamura, Toshikazu Yoshikawa, Natsuo Yasui, Hiroshi Shiota and Mitsuo Itakura : No evidence for association of ENPP1(PC-1)K121Q variant with risk of Type 2 diabetes in a Japanese population., Journal of Human Genetics, Vol.51, No.6, 559-566, 2006.
(要約)
Ecto-nucleotide pyrophosphatase/phosphodiesterase 1 (ENPP1, also known as PC-1) inhibits insulin signal transduction pathway(s). Previous studies have demonstrated the K121Q variant of the ENPP1 gene to have a significant functional role in determining susceptibility to insulin resistance and type 2 diabetes (T2D). To assess whether the K121Q variant has any impact on T2D in Japanese, we undertook an extensive case-control association study using a total of 911 unrelated Japanese T2D patients and 876 control subjects. No significant difference was observed in either genotype distribution (P=0.95) or allele frequency (P=0.83) between T2D and control groups. Notably, the frequency of the ancestral Q121 allele, which is also present in other primates, was quite high in African-Americans, and showed a marked ethnic variation (77.3% in African-Americans, 16.7% in European Americans, 10.5% in Japanese and 4.2% in Han Chinese). Consequently, the pairwise F(ST )value (a classic measure of genetic distance between pairs of population) showed highly significant differentiations between African-American and non-African-American populations (F(ST)>0.3). Our results indicated that the K121Q variant of the ENPP1 gene has very little, if any, impact on T2D susceptibility in Japanese, but may play a role in the inter-ethnic variability in insulin resistance and T2D.
(キーワード)
African Americans / Alleles / Amino Acid Substitution / Asian Continental Ancestry Group / Case-Control Studies / Diabetes Mellitus, Type 2 / European Continental Ancestry Group / Female / Gene Frequency / Genetic Variation / Humans / インスリン抵抗性 (insulin resistance) / 日本 (Japan) / Male / Phosphoric Diester Hydrolases / Pyrophosphatases / Risk Factors
Yoshiki Itoh, Nobuhisa Mizuki, Tsuyako Shimada, Fumihiro Azuma, Mitsuo Itakura, Koichi Kashiwase, Eri Kikkawa, Jerzy K. Kulski, Masahiro Satake and Hidetoshi Inoko : High-throughput DNA typing of HLA-A, -B, -C, and -DRB1 loci by a PCR-SSOP-Luminex method in the Japanese population., Immunogenetics, Vol.57, No.10, 717-729, 2005.
(要約)
We have developed a new high-throughput, high-resolution genotyping method for the detection of alleles at the human leukocyte antigen (HLA)-A, -B, -C, and -DRB1 loci by combining polymerase chain reaction (PCR) and sequence-specific oligonucleotide probes (SSOPs) protocols with the Luminex 100 xMAP flow cytometry dual-laser system to quantitate fluorescently labeled oligonucleotides attached to color-coded microbeads. In order to detect the HLA alleles with a frequency of more than 0.1% in the Japanese population, we created 48 oligonucleotide probes for the HLA-A locus, 61 for HLA-B, 34 for HLA-C, and 51 for HLA-DRB1. The accuracy of the PCR-SSOP-Luminex method was determined by comparing it to the nucleotide sequencing method after subcloning into the plasmid vector using 150 multinational control samples obtained from the International HLA DNA Exchange University of California Los Angeles. In addition, we performed the PCR-SSOP-Luminex method for HLA allele typing on DNA samples collected from 1,018 Japanese volunteers. Overall, the genotyping method exhibited an accuracy of 85.91% for HLA-A, 85.03% for HLA-B, 97.32% for HLA-C, and 90.67% for HLA-DRB1 using 150 control samples, and 100% for HLA-A and -C, 99.90% for HLA-B, and 99.95% for HLA-DRB1 in 1,018 Japanese samples. The PCR-SSOP-Luminex method provides a simple, accurate, and rapid approach toward multiplex genotyping of HLA alleles to the four-digit or higher level of resolution in the Japanese population. It takes only approximately 5 h from DNA extraction to the definition of HLA four-digit alleles at the HLA-A, HLA-B, HLA-C, and HLA-DRB1 loci for 96 samples when handled by a single typist.
Yuki Endo, Lihua Zhang, Katashima Rumi, Mitsuo Itakura, Erin S. A. Doherty, Annelise E. Barron and Yoshinobu Baba : Effect of polymer matrix and glycerol on rapid single-strand conformation polymorphism analysis by capillary and microchip electrophoresis for detection of mutations in K-ras gene, Electrophoresis, Vol.26, No.17, 3380-3386, 2005.
(要約)
We present the rapid single-strand conformation polymorphism (SSCP) analysis by capillary and microchip electrophoresis to detect the mutations in K-ras gene. Parameters that might affect the analysis of mutation in K-ras gene, such as the polymer and the additive in the sieving matrix, have been studied systematically. Under the optimal conditions, the analysis of seven mutants of K-ras gene could be finished within 10 min by capillary electrophoresis (CE). Furthermore, with the wild-type gene as the inner standard, the analysis accuracy of mutations could be improved. In addition, by studying the properties of polymer solutions, the matrix suitable for microchip electrophoresis was found, and the detection of mutations in K-ras gene could be further shortened to 1 min.
Takayuki Ogawa, Takeshi Nikawa, Harumi Furochi, Miki Kosyoji, Katsuya Hirasaka, Naoto Suzue, Koichi Sairyo, Shunji Nakano, Takashi Yamaoka, Mitsuo Itakura, Kyoichi Kishi and Natsuo Yasui : Osteoactivin upregulates expression of MMP-3 and MMP-9 in fibroblasts infiltrated into denervated skeletal muscle in mice, American Journal of Physiology, Cell Physiology, Vol.289, No.3, C697-C707, 2005.
(要約)
In this study, we examined pathophysiological roles of osteoactivin, a functionally unknown type I membrane glycoprotein, in mouse skeletal muscle atrophied by denervation (sciatic neurectomy). Denervation increased the amounts of osteoactivin, vimentin, matrix metalloproteinase-3 (MMP-3), and MMP-9 in mouse gastrocnemius muscle. Interestingly, immunohistochemical analysis revealed that vimentin, MMP-3, and MMP-9 were mainly present in fibroblast-like cells infiltrated into denervated mouse gastrocnemius muscle, whereas osteoactivin was expressed in the sarcolemma of myofibers adjacent to the fibroblast-like cells. On the basis of these findings, we reasoned that osteoactivin in myocytes was involved in activation of the infiltrated fibroblasts. To address this issue, we examined effects of osteoactivin on expression of MMPs in fibroblasts in vitro and in vivo. Overexpression of osteoactivin in NIH-3T3 fibroblasts induced expression of MMP-3, but not in mouse C(2)C(12) myoblasts, indicating that osteoactivin might functionally target fibroblasts. Treatment with recombinant mouse osteoactivin increased the amounts of collagen type I, MMP-3, and MMP-9 in mouse NIH-3T3 fibroblasts. The upregulated expression of these fibroblast marker proteins was significantly inhibited by heparin, but not by an integrin inhibitor, indicating that a heparin-binding motif in the extracellular domain might be an active site of osteoactivin. In osteoactivin-transgenic mice, denervation further enhanced expression of MMP-3 and MMP-9 in fibroblasts infiltrated into gastrocnemius muscle, compared with wild-type mice. Our present results suggest that osteoactivin might function as an activator for fibroblasts infiltrated into denervated skeletal muscles and play an important role in regulating degeneration/regeneration of extracellular matrix.
Tatsuro Miyamoto, Hiroshi Inoue, Yukiko Yamashita, Eiji Kudo, Takeshi Naito, Takako Mikawa, Yoichi Mikawa, Yasushi Isashiki, Dai Osabe, Shuichi Shinohara, Hiroshi Shiota and Mitsuo Itakura : Identification of a novel splice site mutation of the CSPG2 gene in a Japanese family with Wagner syndrome., Investigative Ophthalmology & Visual Science, Vol.46, No.8, 2726-2735, 2005.
(要約)
This linkage study confirmed the genetic homogeneity of the Wagner syndrome. CSPG2 encodes versican, a large chondroitin sulfate proteoglycan, which, in vitreous, binds to hyaluronan and link protein and forms large aggregates that are important for maintaining structural integrity. Although the CSPG2 gene has been excluded as a candidate for causing Wagner syndrome, these data emphasize the necessity of further mutational screening in new families and careful functional characterization.
Satoshi Tsutsumi, Hiroshi Inoue, Yukiko Yamashita, Kuniko Mizuta, Nobuyuki Kamata and Mitsuo Itakura : Molecular cloning and characterization of the murine gnathodiaphyseal dysplasia gene GDD1., Biochemical and Biophysical Research Communications, Vol.331, No.4, 1099-1106, 2005.
(要約)
Mutations in the GDD1 gene cause gnathodiaphyseal dysplasia, a rare human skeletal syndrome with autosomal dominant inheritance. The biochemical function(s) of GDD1 protein and the molecular pathophysiology of GDD1 mutations leading to GDD have not yet been elucidated. In this study, we characterized the complete cDNA sequence and genomic organization of the mouse GDD1 gene. Analysis of GDD1 mRNA revealed a complex alternative splicing pattern, involving five exons of the GDD1 gene. GDD1 isoforms lacking conserved amino acids at the N-terminus cytoplasmic tails, and with changes in transmembrane topology, are presumably associated with changes in protein functions and subcellular localizations of GDD1. We found GDD1 expression to be up-regulated during the course of myogenic differentiation in the murine pluripotent mesenchymal precursor cell line C2C12, whereas its expression was diminished during osteoblastic differentiation. These observations suggest diverse cellular roles of GDD1 protein.
Hiroshi Yaguchi, Katsuhiko Togawa, Maki Moritani and Mitsuo Itakura : Identification of candidate genes in the type 2 diabetes modifier locus using expression QTL, Genomics, Vol.85, No.5, 591-599, 2005.
(要約)
To identify new genetic determinants relevant to type 2 diabetes (T2D), diabetic F2 progeny were generated by intercrossing F1 mice obtained from a cross of BKS.Cg-Lepr(db)+/+m and DBA/2, and T2D-related phenotypes were measured. In the F2 population, increased susceptibility to diabetes and obesity was observed. We also detected the major quantitative trait loci (QTL) modifying the severity of diabetes on chromosome 9, where peaks of logarithm of odds (LOD) overlapped for three traits. To identify candidate genes in the QTL intervals, we combined "expression QTL" (eQTL), taking mRNA levels as quantitative traits, and "interstrain sequence variations, including cSNPs." As a result, four genes were identified from cosegregation of clinical QTL with eQTL and 13 genes were found from interstrain cSNPs as candidates in the T2D modifier QTL. Our combined approach shows the acceleration of the discovery of candidate genes in the QTL of interest, spanning several megabases.
Daisuke Hamada, Yoichiro Takata, Dai Osabe, Kyoko Nomura, Syuichi Shinohara, Hiroshi Egawa, Shunji Nakano, Fumio Shinomiya, Charles R Scafe, Vincent M Reeve, Tatsuro Miyamoto, Maki Moritani, Kiyoshi Kunika, Hiroshi Inoue, Natsuo Yasui and Mitsuo Itakura : Association Between Single-Nucleotide Polymorphisms in the SEC8L1 Gene,Which Encodes a Subunit of the Exocyst Complex,and Rheumatoid Arthritis in a Japanese Population, Arthritis and Rheumatism, Vol.52, No.5, 1371-1380, 2005.
(要約)
To identify rheumatoid arthritis (RA) susceptibility genes in a Japanese population by conducting a large-scale case-control association analysis and linkage disequilibrium (LD) mapping on chromosome 7q31-34, a candidate susceptibility locus identified in a preliminary genome-wide scan in 53 Japanese families, using single-nucleotide polymorphisms (SNPs). We prepared 728 dense, evenly spaced SNPs with a minor allele frequency >0.15 in each gene locus on chromosome 7q31-34. Using these SNPs, a 2-stage case-control analysis was performed on 760 RA patients (157 men and 603 women) and 806 non-RA controls (189 men and 617 women). Haplotypes and LD mapping results were assessed based on SNP genotypes in 380 controls. Forty-eight SNPs showed allele associations (P < 0.05) in the first set of DNA samples (380 RA cases and 380 non-RA controls; first-stage analysis). For 4 of the SNPs in the SEC8L1 gene, the association was replicated (P < 0.05) in the second, independent set of DNA samples (an additional 380 RA cases and 380 non-RA controls; second-stage analysis). When data from the 2 groups were combined, the most significant allele association was observed with SNP 441, an intronic SNP of the SEC8L1 gene (P = 0.000059). The SEC8L1 SNPs with significant allele associations were all located in a single conserved LD block (block 4). Haplotype analysis revealed the disease-risk (P = 0.0015) and disease-protective (P = 0.0000062) haplotypes. Resequencing of coding exons within block 4 did not identify any nonsynonymous SNPs. Real-time quantitative polymerase chain reaction revealed that SEC8L1 was expressed ubiquitously in human tissues, including fibroblast-like synoviocytes from RA patients. Our locus-wide association and LD analyses identified intronic SNPs and haplotypes in the SEC8L1 gene that are strongly associated with RA. We propose that SEC8L1, which encodes a component of the exocyst complex, is a candidate susceptibility gene for RA in the Japanese population.
(キーワード)
Adult / Aged / Arthritis, Rheumatoid / Carrier Proteins / Case-Control Studies / Female / Haplotypes / Humans / Japan / Linkage Disequilibrium / Male / Membrane Proteins / Middle Aged / Polymorphism, Single Nucleotide / Vesicular Transport Proteins
Francisco La De M. Vega, Hadar Isaac, Andrew Collins, Charles R. Scafe, Bjarni V. Halldórsson, Xiaoping Su, Ross A. Lippert, Yu Wang, Marion Laig-Webster, Ryan T. Koehler, Janet S. Ziegle, Lewis T. Wogan, Junko F. Stevens, Kyle M. Leinen, Sheri J. Olson, Karl J. Guegler, Xiaoqing You, Lily H. Xu, Heinz G. Hemken, Francis Kalush, Mitsuo Itakura, Yi Zheng, Guy de Thé, Stephen J. O'Brien, Andrew G. Clark, Sorin Istrail, Michael W. Hunkapiller, Eugene G. Spier and Dennis A. Gilbert : The linkage disequilibrium maps of three human chromosomes across four populations reflect their demographic history and a common underlying recombination pattern, Genome Research, Vol.15, No.4, 454-462, 2005.
(要約)
The extent and patterns of linkage disequilibrium (LD) determine the feasibility of association studies to map genes that underlie complex traits. Here we present a comparison of the patterns of LD across four major human populations (African-American, Caucasian, Chinese, and Japanese) with a high-resolution single-nucleotide polymorphism (SNP) map covering almost the entire length of chromosomes 6, 21, and 22. We constructed metric LD maps formulated such that the units measure the extent of useful LD for association mapping. LD reaches almost twice as far in chromosome 6 as in chromosomes 21 or 22, in agreement with their differences in recombination rates. By all measures used, out-of-Africa populations showed over a third more LD than African-Americans, highlighting the role of the population's demography in shaping the patterns of LD. Despite those differences, the long-range contour of the LD maps is remarkably similar across the four populations, presumably reflecting common localization of recombination hot spots. Our results have practical implications for the rational design and selection of SNPs for disease association studies.
(キーワード)
African Americans / African Continental Ancestry Group / Asian Continental Ancestry Group / Chromosome Mapping / Chromosomes, Human, Pair 21 / Chromosomes, Human, Pair 22 / Chromosomes, Human, Pair 6 / Demography / European Continental Ancestry Group / Genetics, Population / Humans / Linkage Disequilibrium / Polymorphism, Single Nucleotide / Recombination, Genetic
Maki Moritani, Seiji Yamasaki, Mitsuhiro Kagami, Takao Suzuki, Takashi Yamaoka, Toshiaki Sano, Jun-Ichi Hata and Mitsuo Itakura : Hypoplasia of endocrine and exocrine pancreas in homozygous transgenic TGF-β1, Molecular and Cellular Endocrinology, Vol.229, No.1-2, 175-184, 2005.
(要約)
We generated the homozygous transgenic mice with expression of the active form of TGF-beta1 by the glucagon promoter (homozygous NOD-TGF-beta1). The homozygous NOD-TGF-beta1 showed severe diabetes in 84.6%, impaired glucose tolerance, and low serum insulin levels. The final size of endocrine and whole pancreas decreased, respectively, to 6 and 34%, compared to wild-type mice. The homozygous N(2) backcross to C57BL/6 (B6-TGF-beta1) showed no diabetes, but impaired glucose tolerance and low serum insulin levels. In homozygous NOD-TGF-beta1, the expression of p15(INK4b) was induced by 3.4-fold in pancreatic islets than that in wild-type mice. Based on these, we conclude first that excessive paracrine TGF-beta1 signaling in islets results in endocrine and exocrine pancreatic hypoplasia, second that TGF-beta1decrease the final size of endocrine and exocrine pancreas presumably through regulating cell cycle via p15(INK4b) at least in endocrine pancreas, and third that hypoplastic action of TGF-beta1 of pancreatic islets is independent of the genetic background.
S. Hino, Takashi Yamaoka, Y. Yamashita, T. Yamada, J. Hata and Mitsuo Itakura : In vivo proliferation of differentiated pancreatic islet beta cells in transgenic mice expressing mutated cyclin-dependent kinase 4, Diabetologia, Vol.47, No.10, 1819-1830, 2004.
(要約)
It has previously been hypothesised that highly differentiated endocrine cells do not proliferate or regenerate. However, recent studies have revealed that cyclin-dependent kinase 4 (CDK4) is necessary for the proliferation of pancreatic islet beta cells. The aim of this study was to determine whether activation of CDK4 can potentially be used as a radical treatment for diabetes without malignant transformation. We generated transgenic mice expressing mutant CDK4 under the control of the insulin promoter to examine the effect of activated CDK4 overexpression in the postnatal development of pancreatic islets. In the transgenic mice, total CDK4 protein expression was increased by up to 5-fold, with a concomitant increase in CDK4 activity indicated by the detection of phosphorylated Rb protein in pancreatic islets. Histopathologically, many cells tested positive for proliferating cell nuclear antigen, and pancreatic islets displayed hyperplasia due to the extreme proliferation of beta cells containing a large number of insulin granules. Pancreatic islet alpha, delta and PP cells did not increase. Over an 18-month observation period, the transgenic mice did not develop insulinoma. Levels of expression of GLUT1 and c-myc were comparable to those in the littermates of the transgenic mice. GLUT2 expression was identified in the pancreatic islets of transgenic mice. No significant differences in telomerase activities were detected between transgenic mice and their littermates. Transgenic mice were superior to their littermates in terms of glucose tolerance and insulin secretion in response to the intraperitoneal injection of glucose, and hypoglycaemia was not observed. Activated CDK4 stimulates postnatal pancreatic beta cell proliferation, during which the highly differentiated phenotypes of pancreatic islet beta cells are preserved without malignant transformation.
YUYING C. HWANG, MICHIYO KANEKO, SOLIMAN BAKR, HUI LIAO, YAN LU, ERIN R. LEWIS, SHIDU YAN, II SETSUKO, Mitsuo Itakura, LIU RUI, HAL SKOPICKI, SHUNICHI HOMMA, ANN MARIE SCHMIDT, PETER J. OATES, MATTHIAS SZABOLCS and RAVICHANDRAN RAMASAMY : Central role for aldose reductase pathway in myocardial ischemic injury, The FASEB journal, Vol.18, No.11, 1192-1199, 2004.
(キーワード)
cytosolic redox state / glucose metabolism / ischemia-reperfusion injury
Eiji Kudo, Naoyuki Kamatani, Osamu Tezuka, Atsuo Taniguchi, Hisashi Yamanaka, Sachiko Yabe, Dai Osabe, Syuichi Shinohara, Kyoko Nomura, Masaya Segawa, Tatsuro Miyamoto, Maki Moritani, Kiyoshi Kunika and Mitsuo Itakura : Familial juvenile hyperuricemic nephropathy: Detection of mutations in the uromodulin gene in five Japanese families, Kidney International, Vol.65, No.5, 1589-1597, 2004.
(要約)
Familial juvenile hyperuricemic nephropathy (FJHN) is an autosomal-dominant disease characterized by hyperuricemia of underexcretion type, gout, and chronic renal failure. We previously reported linkage on chromosome 16p12 in a large Japanese family designated as family 1 in the present study. Recent reports on the discovery of mutations of the uromodulin (UMOD) gene in families with FJHN encouraged us to screen UMOD mutations in Japanese families with FJHN, including family 1. Six unrelated Japanese families with FJHN were examined for mutations of the UMOD gene by direct sequencing. To confirm the results of the mutation screening, parametric linkage analyses were performed using markers in 16p12 region and around other candidate genes of FJHN. Five separate heterozygous mutations (Cys52Trp, Cys135Ser, Cys195Phe, Trp202Ser, and Pro236Leu) were found in five families, including family 1. All mutations were co-segregated with the disease phenotype in all families, except for family 1, in which an individual in the youngest generation was found as a phenocopy by the genetic testing. Revised multipoint linkage analysis showed that the UMOD gene was located in the interval showing logarithm of odds (LOD) score above 6.0. One family carrying no mutation in the UMOD gene showed no linkage to the medullary cystic kidney disease type 1 (MCKD1) locus, the genes of hepatocyte nuclear factor-1beta (HNF-1beta), or urate transporters URAT1 and hUAT. Our results gave an evidence for the mutation of the UMOD gene in the majority of Japanese families with FJHN. Genetic heterogeneity of FJHN was also confirmed. Genetic testing is necessary for definite diagnosis in some cases especially in the young generation.
Satoshi Tsutsumi, Nobuyuki Kamata, J Tamara Vokes, Yutaka Maruoka, Koichi Nakakuki, Shoji Enomoto, Ken Omura, Teruo Amagasa, Masaru Nagayama, Fumiko Saito-Ohara, Johji Inazawa, Maki Moritani, Takashi Yamaoka, Hiroshi Inoue and Mitsuo Itakura : The novel gene encoding a putative transmembrane protein is mutated in gnathodiaphyseal dysplasia (GDD)., American Journal of Human Genetics, Vol.74, No.6, 1255-1261, 2004.
(要約)
Gnathodiaphyseal dysplasia (GDD) is a rare skeletal syndrome characterized by bone fragility, sclerosis of tubular bones, and cemento-osseous lesions of the jawbone. By linkage analysis of a large Japanese family with GDD, we previously mapped the GDD locus to chromosome 11p14.3-15.1. In the critical region determined by recombination mapping, we identified a novel gene (GDD1) that encodes a 913-amino-acid protein containing eight putative transmembrane-spanning domains. Two missense mutations (C356R and C356G) of GDD1 were identified in the two families with GDD (the original Japanese family and a new African American family), and both missense mutations occur at the cysteine residue at amino acid 356, which is evolutionarily conserved among human, mouse, zebrafish, fruit fly, and mosquito. Cellular localization to the endoplasmic reticulum suggests a role for GDD1 in the regulation of intracellular calcium homeostasis.
Noriko Mizusawa, Tomoko Hasegawa, Izumi Ohigashi, Chisato Kosugi, Nagakatsu Harada, Mitsuo Itakura and Katsuhiko Yoshimoto : Differentiation Penotypes of Pancreatic Islet β- and α-cells are Closely Related with Homeotic Genes and a Group of Differentially Expressed Genes., Gene, Vol.331, No.28, 53-63, 2004.
(要約)
To identify the genes that determine differentiation phenotypes, we compared gene expression of pancreatic islet beta- and alpha-cells, which are derived from the common precursor and secrete insulin and glucagon, respectively. The expression levels of homeotic genes including Hox genes known to determine region specificity in the antero-posterior (AP) body axis, tissue-specific homeobox genes, and other 8,734 genes were compared in a beta- and alpha-cell line of MIN6 and alpha TC1.6. The expression of homeotic genes were surveyed with reverse transcription-polymerase chain reaction (RT-PCR) using degenerate primers corresponding to invariant amino acid sequences within the homeodomain and subsequently with specific primers. Expression of Hoxc6, Hoxc9, Hoxc10, Pdx1, Cdx2, Gbx2, Pax4, and Hlxb9 genes in MIN6 was higher than those in alpha TC1.6, while expression of Hoxa2, Hoxa3, Hoxa5, Hoxa6, Hoxa7, Hoxa9, Hoxa10, Hoxa13, Hoxb3, Hoxb5, Hoxb6, Hoxb13, Hoxb8, and Brain4 genes in alpha TC1.6 was higher than those in MIN6. Out of 8,734 mouse genes screened with high-density mouse cDNA microarrays for MIN6- and alpha TC1.6-derived cDNA, 58 and 25 genes were differentially over- and under-expressed in MIN6, respectively. GLUTag, which is derived from a large bowel tumor and expresses the proglucagon gene, showed a comparatively similar expression profile to that of alpha TC1.6 in both homeotic and other genes analyzed in cDNA microarray. Our results are consistent with the interpretation that not only the tissue-specific homeotic genes, but also Hox genes are related to differentiation phenotypes of pancreatic beta- and alpha-cells rather than their regional specification of the body in vertebrates.
Setsuko Ii, Mika Ohta, Eiji Kudo, Takashi Yamaoka, Tomokazu Tachikawa, Maki Moritani, Mitsuo Itakura and Katsuhiko Yoshimoto : Redox State-Dependent and Sorbitol Accumulation-Independent Diabetic Albuminuria in Mice with Transgene-Derived Human Aldose Reductase and Sorbitol Dehydrogenase Deficiency., Diabetologia, Vol.47, No.3, 541-548, 2004.
(要約)
We investigated the role played by sorbitol accumulation in the kidney in the development of diabetic albuminuria. We created mice ( hAR-Tg:SDH null) with transgene-derived human aldose reductase and sorbitol dehydrogenase (SDH) deficiency, and analysed (i). the contribution of accumulated sorbitol to urinary albumin excretion rate, and (ii). the effect of the aldose reductase inhibitor, epalrestat, on the diabetic redox state, including decreased renal reduced glutathione concentrations or increased lactate to pyruvate ratios in the diabetic kidney. Compared to littermates, non-diabetic transgenic mice had a 2.6-fold increase in aldose reductase mRNA. In a diabetic group, aldose reductase mRNA in hAR-Tg mice was 2.7-fold higher than in littermates. In the diabetic and non-diabetic groups, hAR-Tg:SDH null mice had the highest sorbitol content among all four genetic types including hAR-Tg:SDH null, SDH null, hAR-Tg and littermates. The urinary albumin excretion rate in non-diabetic groups was similar in the four genetic types of mouse. In diabetic groups it was greater than in non-diabetic groups, but did not correlate with the sorbitol content among the four genetic types of mouse. When aldose reductase inhibitor and streptozotocin were given simultaneously at 6 weeks of age, epalrestat prevented diabetic increases in urinary albumin excretion rate and completely prevented diabetic decreases in reduced glutathione concentrations and diabetic increases in lactate to pyruvate ratios, even in the presence of transgenic aldose reductase. The degree of diabetic albuminuria in genetically modified mice is dependent on the redox state and independent of polyol accumulation; aldose reductase inhibitor can prevent diabetic albuminuria by normalising diabetic redox changes.
Masao KITABAYASHI, Yoshiaki NISHIYA, Muneharu ESAKA, Mitsuo Itakura and Tadayuki IMANAKA : Gene Cloning and Function Analysis of Replication Factor C from Thermococcus kodakaraensis KOD1, Bioscience, Biotechnology, and Biochemistry, Vol.67, No.11, 2373-2380, 2003.
(要約)
Replication factor C (RFC) catalyzes the assembly of circular proliferating cell nuclear antigen (PCNA) clamps around primed DNA, enabling processive synthesis by DNA polymerase. The RFC-like genes, arranged in tandem in the Thermococcus kodakaraensis KOD1 genome, were cloned individually and co-expressed in Escherichia coli cells. T. kodakaraensis KOD1 RFC homologue (Tk-RFC) consists of the small subunit (Tk-RFCS: MW=37.2 kDa) and the large subunit (Tk-RFCL: MW=57.2 kDa). The DNA elongation rate of the family B DNA polymerase from T. kodakaraensis KOD1 (KOD DNA polymerase), which has the highest elongation rate in all thermostable DNA polymerases, was increased about 1.7 times, when T. kodakaraensis KOD1 PCNA (Tk-PCNA) and the Tk-RFC at the equal molar ratio of KOD DNA polymerase were reacted with primed DNA.
(キーワード)
replication factor C / clamp loader / DNA polymerase / Thermococcus kodakaraensis KOD1 / proliferating cell nuclear antigen
SATOSHI TSUTSUMI, NOBUYUKI KAMATA, YUTAKA MARUOKA, MIKI ANDO, OSAMU TEZUKA, SHOJI ENOMOTO, KEN OMURA, Masaru Nagayama, Eiji Kudo, MAKI MORITANI, TAKASHI YAMAOKA and Mitsuo Itakura : Autosomal Dominant Gnathodiaphyseal Dysplasia Maps to Chromosome 11p14.3-15.1, Journal of Bone and Mineral Research, Vol.18, No.3, 413-418, 2003.
(要約)
Gnathodiaphyseal dysplasia (GDD) is a syndrome characterized by bone fragility, sclerosis of tubular bones, and cemento-osseous lesions of jawbones. Although some cases of this syndrome exist in families with autosomal dominant inheritance, the underlying gene has never been identified. We analyzed a large four-generation family with GDD by linkage analysis using genomic DNA from nine affected and six nonaffected family members. A genome-wide search using a set of highly polymorphic microsatellite markers showed evidence for linkage to chromosome 11p14.3-15.1. Two-point linkage analysis of microsatellite markers spanning this locus resulted in a maximum logarithm of odds (LOD) score of 2.70 with a recombination fraction (theta) of 0 at D11S1755, D11S1759, and D11S915, and a maximum LOD score of 3.01 at D11S4114 was obtained in multipoint linkage analysis. Haplotype analysis detected no recombination between GDD and six closely linked markers (D11S928, D11S1755, D11S4114, D11S1759, D11S915, and D11S929) and established the candidate interval of 8.7 cM on chromosome 11p for GDD. Although GDD has been considered to be a variation of osteogenesis imperfecta (MIM 166260), our results indicate that this syndrome is a new and distinct disease entity from other systemic bone diseases. Furthermore, these genetic markers are useful for presymptomatic diagnosis of GDD in some families and for identification of the GDD gene.
Soichi Honda, Chisato Kosugi, Shozo Yamada, Toshiaki Sano, Toshio Matsumoto, Mitsuo Itakura and Katsuhiko Yoshimoto : Human Pituitary Adenomas Infrequently Contain Inactivation of Retinoblastoma 1 Gene and Activation of Cyclin Dependent Kinase 4 Gene., Endocrine Journal, Vol.50, No.3, 309-318, 2003.
(要約)
Components of cyclinD1/cyclin-dependent kinase 4 (CDK4)/p16INK4a/pRb pathway are the frequent target of many tumor types. We examined the role of retinoblastoma susceptibility gene (RB1) and the CDK4 gene in human pituitary tumorigenesis. For the RB1 gene, pRb expression and loss of heterozygosity (LOH) on 13q in pituitary adenomas were analysed. Immunostaining of pRb revealed lack of expression in 1 of 29 pituitary adenomas. In 4 of 31 pituitary adenomas, allelic imbalances including LOH of RB1 on 13q14 were detected. Three of 4 pituitary adenomas, in which one adenoma lacked pRb expression, had a common LOH region at least from D13S219 on 13q12.3-q13 to D13S265 on 13q31-32. Interphase fluorescence in situ hybridization with a probe of RB1 showed 2 copies of RB1 gene suggesting that mitotic recombination events, not deletion or chromosome loss, led to LOH in the 3 pituitary adenomas analyzed. All 27 exons, intron-exon boundaries, and essential promoter region of RB1 gene were then sequenced in genomic DNA from 4 pituitary adenomas with allelic imbalance on 13q14 including one adenoma without pRb expression and 3 adenomas with pRb expression. Any somatic mutations, insertions, or microdeletions in the RB1 gene were not detected in 4 pituitary adenomas. Methylation sensitive (MS)-polymerase chain reaction (PCR) and bisulfite sequencing analysis revealed hypomethylated status of CpG islands in the promoter region of the RB1 genes of 4 pituitary adenomas. In addition, activating mutations of CDK4 gene, which is a component of cyclinD1/CDK4/p16INK4a/pRb pathway, were not detected in 31 pituitary adenomas. Based on these results, it is concluded that somatic mutations of the RB1 gene or CDK4 gene do not appear to play a major role in pituitary tumorigenesis. This supports the presence of potential tumor suppressor gene(s) on 13q12.3-q13 to 13q31-32 in pituitary adenomas.
Hiroyuki Yamasaki, Noriko Mizusawa, Shinji Nagahiro, Shozo Yamada, Toshiaki Sano, Mitsuo Itakura and Katsuhiko Yoshimoto : GH-Secreting Pituitary Adenomas Infrequently Contain Inactivating Mutations of PRKAR1A and LOH of 17q23-24., Clinical Endocrinology, Vol.58, No.4, 464-470, 2003.
(要約)
The molecular events leading to the development of GH-secreting pituitary tumours remain largely unknown. Gsalpha (GNAS1) mutations are found in 27-43% of sporadic GH-secreting adenomas in the Caucasian population, but the frequency of GNAS1 mutations in Japanese and Korean acromegalic patients was reported to be lower, 4-9% and 16%, respectively. Other genes responsible for the tumourigenesis of GH-secreting pituitary adenomas have not been detected yet. PRKAR1A, which codes for the RIalpha regulatory subunit of cyclic AMP-dependent protein kinase A (PKA) on 17q23-24, was recently reported to contain inactivating mutations in some Carney complex families, which involved GH-secreting adenomas in about 10%. We re-evaluated the frequency of GNAS1 mutations and investigated PRKAR1A on the hypothesis that it might play a role in the tumourigenesis of GH-secreting adenomas. We analysed exons 8 and 9 of GNAS1 and all exons and the exon-intron boundaries of PRKAR1A with the PCR and by direct sequencing using genomic DNA extracted from 32 GH-secreting pituitary adenomas (30 GH-secreting adenomas, two GH and PRL-secreting adenomas) and 28 corresponding peripheral blood samples, and performed loss of heterozygosity (LOH) analysis of 17q23-24 with four microsatellite markers and intragenic markers of PRKAR1A. Seventeen of 32 (53.1%) tumours showed somatic-activating mutations of GNAS1: 16 (53.3%) of 30 GH-secreting adenomas and one of two GH and PRL-secreting adenomas. Neither inactivating somatic mutations of PRKAR1A nor LOH of 17q23-24 were detected in any of the tumours examined. We reconfirm the important role of activating mutations of GNAS1 in GH-secreting adenomas, and conclude that PRKAR1A does not play a significant role in the tumourigenesis.
Masao KITABAYASHI, Yoshiaki NISHIYA, Muneharu ESAKA, Mitsuo Itakura and Tadayuki IMANAKA : Gene Cloning and Polymerase Chain Reaction with Proliferating Cell Nuclear Antigen from Thermococcus kodakaraensis KOD1, Bioscience, Biotechnology, and Biochemistry, Vol.66, No.10, 2194-2200, 2002.
(要約)
The gene encoding the proliferating cell nuclear antigen (PCNA), a sliding clamp of DNA polymerases, was cloned from an euryarchaeote, Thermococcus kodakaraensis KOD1. The PCNA homologue, designated Tk-PCNA, contained 249 amino acid residues with a calculated molecular mass of 28,200 Da and was 84.3% identical to that from Pyrococcus furiosus. Tk-PCNA was overexpressed in Escherichia coli and purified. This protein stimulated the primer extension abilities of the DNA polymerase from T. kodakaraensis KOD1 'KOD DNA polymerase'. The stimulatory effect of Tk-PCNA was observed when a circular DNA template was used and was equally effective on both circular and linear DNA. The Tk-PCNA improved the sensitivity of PCR without adverse effects on fidelity with the KOD DNA polymerase. This is the first report in which a replication-related factor worked on PCR.
Takashi Yamaoka, Kenji Yoshino, Taketo Yamada, Mikiko Yano, Takefumi Matsui, Takashi Yamaguchi, Maki Moritani, Jun-ichi Hata, Sumihare Noji and Mitsuo Itakura : Transgenic expression of FGF8 and FGF10 induces transdifferentiation of pancreatic islet cells into hepatocytes and exocrine cells, Biochemical and Biophysical Research Communications, Vol.292, No.1, 138-143, 2002.
(要約)
FGF signaling is essential for normal development of pancreatic islets. To examine the effects of overexpressed FGF8 and FGF10 on pancreatic development, we generated FGF8- and FGF10-transgenic mice (Tg mice) under the control of the glucagon promoter. In FGF8-Tg mice, hepatocyte-like cells were observed in the periphery of pancreatic islets, but areas of alpha and beta cells did not decrease, whereas in FGF10-Tg mice, pancreatic ductal and acinar cells were found in islets, concomitantly with disturbed beta-cell differentiation. These results suggest that FGF8 and FGF10 play important roles in development of hepatocytes and exocrine cells, respectively, and explain the absence of FGF8 expression in normal islets and pancreatic hypoplasia in FGF10-deficient mice.
Hidemi Sasaki, Takashi Yamaoka, Hideyo Ohuchi, Akihiro Yasue, Tsutomu Nohno, Hirotaka Kawano, Shigeaki Kato, Mitsuo Itakura, Masaru Nagayama and Sumihare Noji : Identification of cis-elements regulating expression of Fgf10 during limb development., The International Journal of Developmental Biology, Vol.46, No.7, 963-967, 2002.
(要約)
Fibroblast growth factor 10 (FGF10) is known to be expressed in limb mesenchymal cells and to function as a mesenchymal signaling factor involved in epithelial-mesenchymal interactions during limb development. To elucidate regulation of Fgf10 expression, we isolated the promoter region of Fgf10 containing its 2.0 kb upstream 5'-fragment from the initiation codon and its 0.9 kb downstream fragment. Transcriptional activity of the fragment was examined with transgenic mice, using a lacZ-reporter system. Although no significant expression of the reporter gene was observed for the 0.2 kb 5'-fragment, expression was detected in the apical ectodermal ridge of the limb bud and developing cartilage of the limb for the 2.0 kb and 0.7 kb 5'-fragments, respectively. From comparison of the mouse sequences of the 2.0 kb fragment with corresponding sequences of human and chicken Fgf10, we identified 17 conserved putative enhancer motifs for AER expression and other unidentified expressions. For limb cartilage expression, we found putative enhancer sequences conserved among the three species in the 0.7 kb 5'-fragment. In the fragment, three DNA binding motifs were identified in the mouse and human sequence, although they are not conserved in the corresponding chicken sequence.
Iwao Ohno, Kimiyoshi Ichida, Hideaki Okabe, Maki Moritani, Mitsuo Itakura, Masayuki Saito, Naoyuki Kamatani and Tatsuo Hosoya : Familial Juvenile Gouty Nephropathy: Exclusion of 16p12 from the Candidate Locus, Nephron, Vol.92, No.3, 573-575, 2002.
(要約)
Familial juvenile gouty nephropathy (FJGN, MIM 162000) is an autosomal-dominant renal disease characterized by underexcretion-type hyperuricemia, gouty arthritis, and progressive renal disease at younger ages. We analyzed the localization of the responsible gene for FJGN concerning the chromosomal region of 16p12 using parametric linkage analysis in our FJGN. The affected members of this family were accompanied with polyuria due to nephrogenic diabetes insipidus and without hypertension. Fifteen samples were collected from 9 affected and 6 nonaffected members of the family. By using microsatellite markers mainly focused on the short arm of chromosome 16, two point and multipoint linkage analyses were carried out. All of the 2-point logarithm of odds (LOD) scores were typically negative and all of the multipoint LOD scores were less than -3.0 in our FJGN family. The results suggested that the localization of the responsible gene to 16p12 can be excluded in our FJGN family. This finding means that the responsible gene for FJGN is not common.
Takashi Yamaoka, Makiko Yano, Maki Kondo, Hidemi Sasaki, Satoshi Hino, Rumi Katashima, Maki Moritani and Mitsuo Itakura : Feedback Inhibition of Amidophosphoribosyltransferase Regulates the Rate of Cell Growth via Purine Nucleotide, DNA, and Protein Syntheses, The Journal of Biological Chemistry, Vol.276, No.24, 21285-21291, 2001.
(要約)
To clarify the contributions of amidophosphoribosyltransferase (ATase) and its feedback regulation to the rates of purine de novo synthesis, DNA synthesis, protein synthesis, and cell growth, mutated human ATase (mhATase) resistant to feedback inhibition by purine ribonucleotides was engineered by site-directed mutagenesis and expressed in CHO ade (-)A cells (an ATase-deficient cell line of Chinese hamster ovary fibroblasts) and in transgenic mice (mhATase-Tg mice). In Chinese hamster ovary transfectants with mhATase, the following parameters were examined: ATase activity and its subunit structure, the metabolic rates of de novo and salvage pathways, DNA and protein synthesis rates, and the rate of cell growth. In mhATase-Tg mice, ATase activity in the liver and spleen, the metabolic rate of the de novo pathway in the liver, serum uric acid concentration, urinary excretion of purine derivatives, and T lymphocyte proliferation by phytohemagglutinin were examined. We concluded the following. 1) ATase and its feedback inhibition regulate not only the rate of purine de novo synthesis but also DNA and protein synthesis rates and the rate of cell growth in cultured fibroblasts. 2) Suppression of the de novo pathway by the salvage pathway is mainly due to the feedback inhibition of ATase by purine ribonucleotides produced via the salvage pathway, whereas the suppression of the salvage pathway by the de novo pathway is due to consumption of 5-phosphoribosyl 1-pyrophosphate by the de novo pathway. 3) The feedback inhibition of ATase is more important for the regulation of the de novo pathway than that of 5-phosphoribosyl 1-pyrophosphate synthetase. 4) ATase superactivity leads to hyperuricemia and an increased bromodeoxyuridine incorporation in T lymphocytes stimulated by phytohemagglutinin.
Maki Kondo, Takashi Yamaoka, Soichi Honda, Yoshihiro Miwa, Maki Moritani, Kastuhiko Yoshimoto, Yoshio Hayashi and Mitsuo Itakura : The Rate of Cell Growth Is Regulated by Purine Biosynthesis via ATP Production and G to Sphase Transition, The Journal of Biochemistry, Vol.128, No.1, 57-64, 2000.
(要約)
We recently showed that an increased supply of purine nucleotides increased the growth rate of cultured fibroblasts. To understand the mechanism of the growth rate regulation, CHO K1 (a wild type of Chinese hamster ovary fibroblast cell line) and CHO ade (-)A (a cell line deficient in amidophosphoribosyltransferase, a rate-limiting enzyme of the de novo pathway) were cultured under various conditions. Moreover, a defective de novo pathway in CHO ade (-)A cells was exogenously restored by 5-amino-4-imidazole-carboxamide riboside, a precursor of the de novo pathway. The following parameters were determined: the growth rate of CHO fibroblasts, the metabolic rate of the de novo pathway, the enzyme activities of amidophosphoribosyltransferase and hypoxanthine phosphoribosyltransferase, the content of intracellular nucleotides, and the duration of each cell-cycle phase. We concluded the following: (i) Purine de novo synthesis, rather than purine salvage synthesis or pyrimidine synthesis, limits the growth rate. (ii) Purine nucleotides are synthesized preferentially by the salvage pathway as long as hypoxanthine is available for energy conservation. (iii) The GTP content depends on the intracellular ATP content. (iv) Biosynthesis of purine nucleotides increases the growth rate mainly through ATP production and promotion of the G(1)/S transition.
Naoyuki Kamatani, Maki Moritani, Hisashi Yamanaka, Fujio Takeuchi, Tatsuo Hosoya and Mitsuo Itakura : Localization of a gene for familial juvenile hyperuricemic nephropathy causing underexcretion-type gout to 16p12 by genome-wide linkage analysis of a large family., Arthritis and Rheumatism, Vol.43, No.4, 925-929, 2000.
(要約)
Familial juvenile hyperuricemic nephropathy (FJHN, MIM 162000) is an autosomal-dominant disease characterized by underexcretion-type hyperuricemia, gout, and chronic renal failure. No loci responsible for this disease or any underexcretion-type hyperuricemia/gout have ever been identified. The aim of the study was to localize a gene responsible for FJHN by linkage analysis. A single large family with at least 20 affected members was analyzed. DNA was obtained from 13 affected and 18 non-affected members after lymphoblastoid cell lines were established. Initially, polymorphic data were obtained for 343 microsatellite loci covering all chromosomes except the X chromosome. Parametric linkage analysis was performed using the obtained data with LINKAGE package software. Following a genome-wide search using a set of highly polymorphic microsatellite markers, initial evidence for linkage was obtained for a marker on chromosome 16p. We subsequently genotyped the same subjects for 12 additional markers spanning approximately 30 cM on the short arm of chromosome 16. We obtained a maximum 2-point logarithm of odds (LOD) score of 6.04 at theta = 0 with the marker D16S401; multipoint linkage analysis yielded a maximum LOD score of 6.14 with markers D16S401 and D16S3113, and established a minimum candidate interval of approximately 9 cM. A gene for FJHN was localized to a candidate interval of approximately 9 cM at 16p12. These findings will be useful for the presymptomatic diagnosis of FJHN in some families and for testing genetic heterogeneity of FJHN in general.
Kenji Sasahara, Takashi Yamaoka, Maki Moritani, Katsuhiko Yoshimoto, Yasuhiro Kuroda and Mitsuo Itakura : Molecular Cloning and Tissue-specific Expression of a New Member of the Regenerating Protein Family, Islet Neogenesis-associated Protein-related Protein., Biochimica et Biophysica Acta (BBA) - Molecular Basis of Disease, Vol.1500, No.1, 142-146, 2000.
(要約)
Islet neogenesis-associated protein (INGAP) is a protein expressed during islet neogenesis. We have cloned a novel cDNA having a similar sequence to INGAP cDNA. The cDNA encodes 175 amino acids designated INGAP-related protein (INGAPrP). INGAP is expressed in cellophane-wrapped pancreas, but not in normal pancreas, whereas INGAPrP was abundantly expressed in normal pancreas.
Takashi Yamaoka, Kenji Yoshino, Taketo Yamada, Chiyoko Idehara, MO Hoque, Maki Moritani, Katsuhiko Yoshimoto, Jun-ichi Hata and Mitsuo Itakura : Diabetes and tumor formation in transgenic mice expressing reg I., Biochemical and Biophysical Research Communications, Vol.278, No.2, 368-376, 2000.
(要約)
To examine the effect of overexpressed regenerating gene (Reg) I on pancreatic beta-cells, we generated transgenic mice expressing Reg I in islets (Reg-Tg mice). Three lines of Reg-Tg mice were established. In line-1 Reg-Tg mice, the expression level of Reg I mRNA in islets was 7 times higher than those in lines 2 and 3 of Reg-Tg mice, and line 1 mice developed diabetes by apoptosis of beta-cells, as well as various malignant tumors. In addition to the decrease in beta-cells, compensatory islet regeneration and proliferation of ductal epithelial cells were observed in line-1 Reg-Tg mice. Because Reg I protein was secreted primarily into pancreatic ducts from acinar cells, it may primarily stimulate the proliferation of ductal epithelial cells, and not beta-cells, and their differentiation into islets. Moreover, the tumor-promoting activity of Reg I protein should be considered for its possible clinical applications.
Maki Kondo, Takashi Yamaoka, Soichi Honda, Yoshihiro Miwa, Rumi Katashima, Maki Moritani, Katsuhiko Yoshimoto, Yoshio Hayashi and Mitsuo Itakura : The Rate of Cell Growth is Regulated by Purine Biosynthesis via ATP Production and G1 to S Phase Transition., The Journal of Biochemistry, Vol.128, No.1, 57-64, 2000.
81.
Takashi Yamaoka, Makiko Yano, Taketo Yamada, Takashi Matsushita, Maki Moritani, Setsuko Ii, Katsuhiko Yoshimoto, Junichi Hata and Mitsuo Itakura : Diabetes and pancreatic tumours in transgenic mice expressing Pax6., Diabetologia, Vol.43, No.3, 332-339, 2000.
(要約)
Both endocrine and exocrine cells of the pancreas differentiate from epithelial cells of primitive pancreatic ducts, and four types of pancreatic islet cells (alpha, beta, delta, and PP cells) are derived from the common pluripotent precursor cells. Although Pa x 6 is expressed in all islet cells, Pa x 4 is detected only in beta cells. In homozygous Pa x 4-null mice, beta cells are absent, whereas the number of alpha cells is increased. Therefore, we hypothesized that the balance of Pa x 4 and 6 is one of the determinants by which the common progenitor cells differentiate into alpha or beta cells. To change this balance, we generated transgenic mice overexpressing Pa x 6 driven by the insulin promoter or the PDX1 promoter. In both types of transgenic mice, normal development of beta cells was disturbed, resulting in apoptosis of beta cells and diabetes. In Insulin/Pa x 6-Tg mice, beta cells were specifically affected, whereas in PDX/Pa x 6-Tg mice, developmental abnormalities involved the whole pancreas including hypoplasia of the exocrine pancreas. Furthermore, PDX/Pa x 6-Tg mice experienced proliferation of both ductal epithelia and islet cells and subsequent cystic adenoma of the pancreas. These findings suggest that Pa x 6 promotes the growth of ductal epithelia and endocrine progenitor cells and that the suppression of Pa x 6 is necessary for the normal development of beta cells and the exocrine pancreas.
Kenji Sasahara, Takashi Yamaoka, Maki Moritani, Masaki Tanaka, Hiroyuki Iwahana, Katsuhiko Yoshimoto, Jun-ichi Miyagawa, Yasuhiro Kuroda and Mitsuo Itakura : Molecular Cloning and Expression Analysis of a Putative Nuclear Protein, SR-25., Biochemical and Biophysical Research Communications, Vol.269, No.2, 444-450, 2000.
(要約)
We cloned a full-length mouse cDNA and its human homologue encoding a novel protein designated as "SR-25." In Northern blot analysis, SR-25 mRNA was expressed in all organs tested, and relatively abundant in testis and thymus. Deduced amino acid sequences of mouse SR-25 and human SR-25 showed 77.7% identity. SR-25 has a serine-arginine repeat (SR repeat) and two types of amino acid clusters: a serine cluster and a highly basic cluster. Based on the presence of many nuclear localizing signals and a similarity to RNA splicing proteins, SR-25 is strongly suggested to be a nuclear protein and may contribute to RNA splicing.
Takumi Abe, Katsuhiko Yoshimoto, Matsuo Taniyama, Kazuo Hanakawa, Hitoshi Izumiyama, Mitsuo Itakura and Kiyoshi Matsumoto : A Germline Mutation of the Multiple Endocrine Neoplasia Type 1 (MEN1) Gene in Japanese Prolactinoma Variant., The Journal of Clinical Endocrinology and Metabolism, Vol.85, No.3, 1327-1330, 2000.
84.
Toru Kikutsuji, Masamitsu Harada, Seiki Tashiro, Setsuko Ii, Maki Moritani, Takashi Yamaoka and Mitsuo Itakura : Expression of somatostatin receptor subtypes and growth inhibition in human exocrine pancreatic cancers., Journal of Hepato-Biliary-Pancreatic Surgery, Vol.7, No.5, 496-503, 2000.
(要約)
The antiproliferative effects of somatostatin and its analogs on human pancreatic cancers were studied: (1) by evaluating the gene expression of somatostatin receptor (sstr) subtypes in human pancreatic cancer cell lines and cancer tissue specimens, (2) by evaluating the antiproliferative effects of somatostatin analogs, and (3) by evaluating the effect of sstr-2 cDNA transduction. Using a reverse transcriptase polymerase chain reaction (RT-PCR), the gene expression of five sstr subtypes (sstr-1 to -5) was examined in eight cell lines, and in ten pancreatic cancer tissues and in the normal surrounding pancreatic tissues. The antiproliferative effects of somatostatin (SS) -14 and its two analogs (SMS 201-995, RC-160) were examined by means of an MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (thiazolyl blue)) assay on three cell lines and Panc-1 transfectants with human sstr (hsstr)-2A cDNA. Sstr-2 was expressed in all samples tested. All examined cell lines simultaneously expressed sstr-2 and -5, while most of the examined pancreatic cancer tissues did not express both of these subtypes simultaneously. Somatostatin analogs inhibited epidermal growth factor (EGF)-stimulated pancreatic cancer cell proliferation. The cell proliferation was further and significantly inhibited by 14% in stable transfectants of Panc-1 cells with hsstr-2A. Based on these findings, it is concluded that somatostatin analogs with their antiproliferative effects mediated by sstr-2 could be potentially useful in the treatment of pancreatic cancers.
Akira Tomonari, Katsuhiko Yoshimoto, Noriko Mizusawa, Hiroyuki Iwahana and Mitsuo Itakura : Differential Regulation of the Human Insulin Gene Transcription by GG1 and GG2 Elements with GG- and C1-binding Factors., Biochimica et Biophysica Acta (BBA) - Gene Structure and Expression, Vol.1446, No.3, 233-242, 1999.
(要約)
Using a human growth hormone reporter system, the introduced mutations in GG1 alone or both GG elements of GG1 and GG2 in the human insulin promoter abolished 94 or 96% of the beta-cell-specific transcriptional activity in a pancreatic islet beta-cell line of MIN6, while the mutations in GG2 or its total deletion abolished 85 or 86% of the transcriptional activity. When linked to the thymidine kinase promoter, mutations in GG1 or both GG elements abolished 74% of the transcriptional activity in MIN6 cells, while the mutations in GG2 or its total deletion abolished 55 or 54%. In the electrophoretic mobility shift assay (EMSA), one nuclear factor was shown to interact with two GG elements, and another C1-binding factor with GG1 and C1. The differential effects of deletions or selective mutations in the GG2 or GG1 sequence in the oligonucleotide probes on the binding activity of GG- or C1-binding factors in EMSA proved the requirement of both GG1 and GG2 or both GG1 and C1, respectively, for the transaction of these two factors. The molecular size of the GG-binding factor was estimated about 30 kDa. Based on these, we conclude that two GG elements contribute, with GG1 more critically than GG2, to the beta-cell-specific transcription of the human insulin gene through transaction with the GG- and C1-binding factors.
Takashi Yamaoka, Makiko Yano, Chiyoko Idehara, Sachiko Tomonari, Maki Moritani, Setsuko Ii, Katsuhiko Yoshimoto, Junichi Hata and Mitsuo Itakura : Apotosis and Remodelling of Beta Cells by Paracrine Interferon-g without Insulitis in Transgenic Mice., Diabetologia, Vol.42, 566-573, 1999.
87.
Katsuhiko Yoshimoto, Chisato Kosugi, Miki Moritani, Eiji Shimizu, Takashi Yamaoka, Shozo Yamada, Toshiaki Sano and Mitsuo Itakura : Infrequent Detectable Somatic Mutations of the RET and Glial Cell Line-Derived Neurotrophic Factor (GDNF) Genes in Human Pituitary Adenomas., Endocrine Journal, Vol.46, No.1, 199-207, 1999.
(要約)
RET is a receptor tyrosine kinase expressed in neuroendocrine cells and tumors. RET is activated by a ligand complex comprising glial cell line-derived neurotrophic factor (GDNF) and GDNF receptor-alpha (GDNFR-alpha). Activating mutations of the RET proto-oncogene were found in multiple endocrine neoplasia (MEN) 2 and in sporadic medullary thyroid carcinoma and pheochromocytoma of neuroendocrine origin. Mutations of the RET proto-oncogene and the glial cell line-derived neurotrophic factor (GDNF) gene were examined in human pituitary tumors. No mutations of the RET proto-oncogene including the cysteine-rich region or codon 768 and 918 in the tyrosine kinase domain were detected in 172 human pituitary adenomas either by polymerase chain reaction (PCR)-single strand conformation polymorphism (SSCP) or by PCR-restriction fragment length polymorphism (RFLP). Further, somatic mutations of the GDNF gene in 33 human pituitary adenomas were not detected by PCR-SSCP. One polymorphism of the GDNF gene at codon 145 of TGC or TGT was observed in a prolactinoma. The RET proto-oncogene message was detected in a normal human pituitary gland or 4 of 4 human pituitary adenomas with reverse transcription (RT)-PCR, and in rodent pituitary tumor cell lines with Western blotting. The expression of GDNF gene was detected in 1 of 4 human somatotroph adenomas, 1 of 2 corticotroph adenomas, and 2 of 6 rodent pituitary tumor cell lines with RT-PCR. Based on these, it is concluded that somatic mutations of the RET proto-oncogene or the GDNF gene do not appear to play a major role in the pituitary tumorigenesis in examined tumors.
Eiji Kudo, Hiroshi Shiota, Takeshi Naito, K Satake and Mitsuo Itakura : Polymorphisms of Thymidine Kinase Gene in Herpes Simplex Virus Type 1, --- Analysis of Clinical Isolates From Herpetic Keratitis Patients and Laboratory Strains ---, Journal of Medical Virology, Vol.56, No.2, 151-158, 1998.
(要約)
Drug-resistance of herpes simplex virus (HSV) is caused most frequently by mutation of the viral thymidine kinase (TK) gene. To elucidate the significance of detecting nucleotide changes of the TK gene for screening drug-resistant viruses, the frequency and variation of the genetic polymorphisms in the whole coding region of the TK gene were studied in 14 acyclovir-susceptible HSV type 1 (HSV-1) clinical isolates from 14 patients with epithelial herpetic keratitis. Two reference HSV-1 laboratory strains, McKrae and PH, and two acyclovir-resistant variants of the PH strain were also studied as controls. Polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP) and direct sequencing detected nucleotide differences at 24 positions, and amino acid substitutions at 12 codons in the TK gene of the examined viruses. Nucleotide diversity of 0.0029 per base (the average number of nucleotide substitutions of 3.3 per 1,131 base pairs) in the TK gene in the clinical isolates was comparable to 0.0037 per base of the whole HSV-1 genome in Japanese isolates reported previously. PCR-SSCP analysis of the acyclovir-resistant strains easily detected aberrantly shifted bands by comparing them with those of the parental strain, followed by the quick determination of mutated sequences. These results suggest that detection of nucleotide changes of the TK gene is useful for serial observation of persistent or recurrent HSV infection as observed in immunocompromised hosts, but that it is not useful for screening drug-resistant viruses from nonepidemic clinical isolates because of the comparable genetic polymorphisms in the TK gene as in the whole HSV-1 genome.
Chisato Kosugi, Takehiko Kimura, Peng Yang, Maki Moritani, Takashi Yamaoka, Shozo Yamada, Toshiaki Sano, Katsuhiko Yoshimoto and Mitsuo Itakura : Analysis of loss of heterozygosity on chromosome 11 and infrequent inactivation of the MEN1 gene in sporadic pituitary adenomas, The Journal of Clinical Endocrinology and Metabolism, Vol.83, No.8, 2631-2634, 1998.
(要約)
To investigate the role of tumor suppressor genes in sporadic pituitary adenomas, we first analyzed loss of heterozygosity on 11q13 with microsatellite analysis in 31 tumors. Loss of heterozygosity on 11q13 was detected in 1 mixed GH/PRL adenoma, and the somatic 22-bp deletion of the multiple endocrine neoplasia type 1 (MEN1) gene encoding menin was detected in this tumor. Trisomy 11 suggested by the decreased mean allelic ratios of 66% or 65% for 16 or 13 microsatellite markers, respectively, in 2 of 31 pituitary adenomas was confirmed by interphase fluorescence in situ hybridization. Screening for mutations of the MEN1 gene did not find mutations with PCR-single strand conformation polymorphism analysis in other pituitary adenomas retaining heterozygosity on 11q13. Based on these, it is concluded that inactivation of the MEN1 gene comprises a rare etiology for tumorigenesis of the pituitary gland, and that trisomy 11 or another gene(s) may contribute to the pathogenesis of sporadic pituitary adenomas.
Takashi Yamaoka, Chiyoko Idehara, Makiko Yano, Takaya Matsushita, Taketo Yamada, Setsuko Ii, Maki Moritani, Jun-ichi Hata, Hiromu Sugino, Sumihare Noji and Mitsuo Itakura : Hypoplasia of pancreatic islets in transgenic mice expressing activin receptor mutants, The Journal of Clinical Investigation, Vol.102, No.2, 294-301, 1998.
(要約)
Activin, a member of the TGF-beta superfamily, regulates the growth and differentiation of a variety of cell types. Based on the expression of activin in pancreatic rudiments of rat embryos and stimulation of insulin secretion from adult rat pancreatic islets by activin, activin is implicated in the development and function of islets. To examine the significance of activin signaling in the fetal and postnatal development of islets, transgenic mice expressing a dominant negative form of activin receptor (dn-ActR) or a constitutively active form of activin receptor (ActR-T206D) in islets were generated together with the transgenic mice expressing intact activin receptor (intact ActR) as a negative control. Transgenic mice with both dn-ActR and ActR-T206D showed lower survival rates, smaller islet area, and lower insulin content in the whole pancreas with impaired glucose tolerance when compared with transgenic mice with intact ActR or littermates, but they showed the same alpha cell/beta cell ratios as their littermates. In addition to islet hypoplasia, the insulin response to glucose was severely impaired in dn-ActR transgenic mice. It is suggested that a precisely regulated intensity of activin signaling is necessary for the normal development of islets at the stage before differentiation into alpha and beta cells, and that activin plays a role in the postnatal functional maturation of islet beta cells.
Chisato Kosugi, Katsuhiko Yoshimoto and Mitsuo Itakura : Germ-Line Mutations in MEN1 Patients-Authors' Response., The Journal of Clinical Endocrinology and Metabolism, Vol.83, No.8, 3005, 1998.
93.
Chisato Kosugi, Takehiko Kimura, Peng Yang, Maki Moritani, Takashi Yamaoka, Shozo Yamada, Toshiaki Sano, Katsuhiko Yoshimoto and Mitsuo Itakura : Analysis of Loss of Heterozygosity on Chromosome 11 and Infrequent Inactivation of MEN1 Gene in Sporadic Pituitary Adenomas., The Journal of Clinical Endocrinology and Metabolism, Vol.83, No.8, 2631-2634, 1998.
94.
Chisato Kosugi, Katsuhiko Yoshimoto, Shozo Yamada, Hiroshi Nishioka, Setsuko Ii, Maki Moritani, Takashi Yamaoka and Mitsuo Itakura : Absence of Germline Mutations of the MEN1 Gene in Familial Pituitary Adenoma in Contrast to Multiple Endocrine Neoplasia Type 1 in Japanese., The Journal of Clinical Endocrinology and Metabolism, Vol.83, No.3, 960-965, 1998.
Familial isolated primary hyperparathyroidism (FIHP) is a rare hereditary disorder. We present four patients from a single family with FIHP, and genetic analysis of their parathyroid adenomas and parathyroid carcinoma. DNA was extracted from tumours resected at surgery. Tumours were examined for loss of heterozygosity (LOH) with microsatellite polymorphic markers. The 27-year-old proband (Patient 1) died of parathyroid carcinoma with metastases to the lungs and chest wall. Sixteen years later, his 34-year-old sister (Patient 2) presented with a neck tumour and primary hyperparathyroidism. Family screening revealed parathyroid tumours in his 36-year-old sister (Patient 3) and 29-year-old cousin (Patient 4). Histological examination of resected tumours showed parathyroid carcinoma and adenoma in Patient 2, a parathyroid adenoma in Patient 3, and an atypical parathyroid adenoma in Patient 4. Autopsy of the proband ruled out multiple endocrine neoplasia (MEN) type 1, and the three patients who underwent parathyroidectomy did not exhibit any abnormalities in the pancreas or the pituitary gland. Analysis of tumour DNA from one parathyroid carcinoma (Patient 2), the atypical parathyroid adenoma (Patient 4), and two parathyroid adenomas (Patients 2 and 3) showed limited LOH on chromosomes 13q12.3-q32 in an adenoma of Patient 2 and 9p21-p22 and 13q12.3-q32 in an adenoma of Patient 3. These results suggest the possible contribution of tumour suppressor genes including the retinoblastoma gene and the hereditary breast cancer susceptibility gene (BRCA2) on 13q to parathyroid tumours in this family.
Chisato Kosugi, Katsuhiko Yoshimoto, Peng Yang, Takehiko Kimura, Shozo Yamada, Maki Moritani, Toshiaki Sano and Mitsuo Itakura : Infrequent Mutations of p27Kip1 Gene and Trisomy 12 in a Subset of Human Pituitary Adenomas., The Journal of Clinical Endocrinology and Metabolism, Vol.82, No.9, 3141-3147, 1997.
98.
Takashi Yamaoka, Maki Kondo, Soichi Honda, Hiroyuki Iwahana, Maki Moritani, Setsuko Ii, Katsuhiko Yoshimoto and Mitsuo Itakura : Amidophosphoribosyltransferase Limits the Rate of Cell Growth-linked de Novo Purine Biosynthesis in the Presence of Constant Capacity of Salvage Purine Biosynthesis., The Journal of Biological Chemistry, Vol.272, No.28, 17719-17725, 1997.
99.
Hongzhong Min, Eiji Kudo, Akiko Hino, Katsuhiko Yoshimoto, Hiroshi Iwahana, Mitsuo Itakura and Keisuke Izumi : p53 Gene Mutation in N-(4-hydroxybutyl) nitrosamine-induced Urinary Bladder Tumors and N-methyl-N-nitrosourea-induced Colon Tumors of Rats., Cancer Letters, Vol.117, No.1, 81-86, 1997.
Hiroshi Sarui, Katsuhiko Yoshimoto, Shoji Okumura, Masanori Kamura, Hiroshi Takuno, Tatsuo Ishizuka, Hiroshi Takao, Kuniyasu Shimokawa, Mitsuo Itakura, Shigetoyo Saji and Keigo Yasuda : Cystic Glucagonoma with Loss of Heterozygosity on chromosome 11 in Multiple Endocrine Neoplasia Type 1., Clinical Endocrinology, Vol.46, No.4, 511-516, 1997.
(要約)
A 52-year-old man with a past history of a pituitary adenoma and hyperparathyroidism due to a parathyroid adenoma was admitted because of a solitary tumour of the pancreas revealed by ultrasonography. His family history was unremarkable. Plasma glucagon levels were slightly elevated (280 ng/l, normal range, 40-180 ng/l) with decreased plasma amino acid levels. Plasma glucagon levels disclosed an exaggerated response during an arginine infusion test and paradoxical elevation during a 75 g oral glucose tolerance test. Endoscopic ultrasonography revealed a monolocular cystic mass of about 3 cm in diameter in the body of the pancreas. A pancreatic tumour was diagnosed before surgery as a cystic glucagonoma. Intra-operative ultrasonography showed one cystic mass in the body of pancreas and two other solid tumours, about 1 cm and 0.5 cm in diameter, in the tail of the pancreas. Histologically, all three tumours showed neoplastic epithelial cells with round nuclei forming cords and/or a ribbon-like arrangement. They showed positive staining for Grimelius' silver stain and immunopositive cells for glucagon. Genetic analysis of the main cystic tumour revealed loss of heterozygosity (LOH) on chromosome 11. After the operation, the responses of plasma glucagon to arginine infusion and oral glucose became normal. Here we describe the usefulness of these provocation tests for early diagnosis and post-operative follow-up in a rare cystic glucagonoma associated with multiple endocrine neoplasia type 1 (MEN 1) which had LOH on chromosome 11.
Yoshihiro Ninomiya, Yoshio Urano, Katsuhiko Yoshimoto, Hiroyuki Iwahana, Shiro Sasaki, Seiji Arase and Mitsuo Itakura : p53 Gene Mutation Analysis in Porokeratosis and Porokeratosis-associated Squamous Cell Carcinoma., Journal of Dermatological Science, Vol.14, No.3, 173-178, 1997.
(要約)
In this and previous studies, we have shown p53 overexpression immunohistochemically in 14 of 17 porokeratotic specimens obtained from 14 lesions of nine cases, and in all six specimens of squamous cell carcinoma (SCC) arising on porokeratotic lesions of two cases. We screened mutations in exons 5 to 10 of the p53 gene in all these specimens by polymerase chain reaction-single strand conformation polymorphism analysis. Mutations of the p53 gene were detected in two of the six SCCs but not in any of the 17 porokeratotic specimens. These two mutations were C to T transitions at codons 146 and 175 in exon 5, which were a nonsense mutation at a dipyrimidine site and a missense mutation at a CG site, respectively. To our knowledge, neither of these mutations has been identified in skin cancers before. Our observations indicate that mutations of the p53 gene are not the major molecular etiology for porokeratosis, but are related to its skin carcinogenesis, and that p53 overexpression in porokeratosis is not due to p53 gene mutations.
Katsuhiko Yoshimoto, Chisato Kosugi, Shozo Yamaza, Takehiko Kimura, Hiroyuki Iwahana, Toshiaki Sano and Mitsuo Itakura : Infrequent Mutations of p16INK4A and p15INK4B Genes in Human Pituitary Adenomas., European Journal of Endocrinology, Vol.136, No.1, 74-80, 1997.
103.
Shozo Yamada, Katsuhiko Yoshimoto, Toshiaki Sano, Kouji Tanaka, Mitsuo Itakura, Mitsuo Usui and Akira Teramoto : Inactivation of the Tumor Suppressor Gene on 11q13 in Brothers with Familial Acrogigantism without Multiple Endocrine Neoplasia Type 1., The Journal of Clinical Investigation, Vol.82, 239-242, 1997.
104.
Maki Moritani, Katsuhiko Yoshimoto, Setsuko Ii, Maki Kondo, Hiroyuki Iwahana, Takashi Yamaoka, Toshiaki Sano, Naoko Nakano, Hitoshi Kikutani and Mitsuo Itakura : Prevention of Adoptively Transferred Diabetes in Non-Obese Diabetic Mice with IL-10-Transduced Islet-Specific Th1 Lymphocytes: A Gene Therapy Model for Autoimmune Diabetes., The Journal of Clinical Investigation, Vol.98, No.8, 1851-1859, 1996.
Satoshi Otsuka, Masaki Tanaka, Shiro Saito, Katsuhiko Yoshimoto and Mitsuo Itakura : Molecular Cloning of a cDNA Encoding Human Ribosomal Protein L39., Biochimica et Biophysica Acta (BBA) - Gene Structure and Expression, Vol.1308, No.2, 119-121, 1996.
(要約)
A cDNA clone encoding a human ribosomal protein L39 (hRPL39) was isolated through a random cDNA sequencing approach to a cDNA library constructed from a human colon carcinoma cell line of COLO 205. Although levels of hRPL39 mRNA were different in several cell lines including carcinoma cell lines from different tissues, they were shown not to be cell cycle-dependent in a human fibroblast cell line of TIG-1.
Hiroyuki Iwahana, Miwa Fujimura, Setsuko Ii, Maki Kondo, Maki Moritani, Yoko Takahashi, Takashi Yamaoka, Katsuhiko Yoshimoto and Mitsuo Itakura : Molecular Cloning of a Human cDNA Encoding a Trifunctional Enzyme of Carbamoyl- Phosphate Synthetase-Aspartate Transcarbamoylase-Dihydroorotase in de Novo Pyrimidine Synthesis., Biochemical and Biophysical Research Communications, Vol.219, No.1, 249-255, 1996.
107.
Chiyo Horie, Hiroyuki Iwahana, Takahiro Horie, Ichiro Shimizu, Katsuhiko Yoshimoto, Shiro Yogita, Seiki Tashiro, Susumu Ito and Mitsuo Itakura : Detection of Different Quasispecies of Hepatitis C Virus Core Region in Cancerous and Non-cancerous Regions., Biochemical and Biophysical Research Communications, Vol.218, No.3, 674-681, 1996.
108.
Akira Tomonari, Katsuhiko Yoshimoto, Masaki Tanaka, Hiroyuki Iwahana, Jun-ichi Miyazaki and Mitsuo Itakura : GGAAT Motifs Play a Major Role in Transcriptional Activity of the Human Insulin Gene in a Pancreatic Islet Beta Cell Line of MIN6., Diabetologia, Vol.39, 1462-1468, 1996.
109.
Hiroyuki Iwahana, Miwa Fujimura, Yoko Takahashi, Katsuhiko Yoshimoto and Mitsuo Itakura : Multiple Fluorescence-Based PCR-SSCP Analysis Using Internal Fluorescent Labeling of PCR Products., BioTechniques, Vol.21, No.3, 510-519, 1996.
110.
Katsuhiko Yoshimoto, Takehiko Kimura, Chisato Kosugi, Maki Moritani, Hiroyuki Iwahana and Mitsuo Itakura : Absence of Mutations at Codon 768 of the RET Proto-Oncogene in Sporadic and Hereditary Pheochromocytomas., Endocrine Journal, Vol.43, No.1, 109-114, 1996.
(要約)
Sixteen sporadic pheochromocytomas, 3 pheochromocytomas in neurofibromatosis 1, and 4 pheochromocytomas in multiple endocrine neoplasia (MEN) 2A or 2B were screened for mutations at codon 768 of the RET proto-oncogene by AluI digestion of polymerase chain reaction PCR products and mutations in exon 13 by PCR-single strand conformation polymorphism (SSCP) analysis. Although mutations at codon 768 (GAG --> GAC; Glu --> Asp) of the RET proto-oncogene were recently reported to be found in 40% of sporadic medullary thyroid carcinomas (MTCs), the absence of missense mutations at codon 768 was confirmed both with PCR-restriction fragment length polymorphism (RFLP) and PCR-SSCP analysis in all examined cases of pheochromocytomas. These results suggest that mutations at codon 768 of the RET proto-oncogene do not represent a frequent mechanism of tumorigenesis for both sporadic and hereditary pheochromocytomas.
Takehiko Kimura, Katsuhiko Yoshimoto, Chisato Kosugi, Yoshihiro Ohkura, Hiroyuki Iwahana, Akira Miyauchi, Toshiaki Sano and Mitsuo Itakura : Obvious mRNA and Protein Expression but Absence of Mutations of the RET Proto-Oncogene in Parathyroid Tumors., European Journal of Endocrinology, Vol.134, No.3, 314-319, 1996.
112.
Yoshio Urano, Takashi Asano, Katsuhiko Yoshimoto, Hiroyuki Iwahana, Yoshiaki Kubo, Shoji Kato, Shiro Sasaki, Norifumi Takeuchi, Naoyuki Uchida, Hideki Nakanishi, Seiji Arase and Mitsuo Itakura : Frequent p53 Accumulation in the Chronically Sun-Exposed Epidermis and Clonal Expansion of p53 Mutant Cells in the Epidermis Adjacent to Basal Cell Carcinoma., The Journal of Investigative Dermatology, Vol.104, No.6, 928-932, 1995.
113.
Hiroyuki Iwanaha, Soichi Honda, Toshiyuki Tsujisawa, Yoko Takahashi, Kyo Adzuma, Rumi Katashima, Takashi Yamaoka, Maki Moritani, Katsuhiko Yoshimoto and Mitsuo Itakura : Rat Genomic Structure of Amidophosphoribosyltransferase, cDNA Sequence of Aminoimidazole Ribonucleotide Carboxylase, and Cell Cycle-Dependent Expression of These Two Physically Linked Genes., Biochimica et Biophysica Acta (BBA) - Gene Structure and Expression, Vol.1261, No.3, 369-380, 1995.
(要約)
Genomic structure of rat amidophosphoribosyltransferase (ATase; EC 2.4.2.14), which catalyzes the first committed step in de novo purine nucleotide synthesis, was determined by polymerase chain reaction (PCR)-based methods. There are 11 exons and all exon-intron boundaries were conserved among rat, human, and chicken ATase genes. A rat aminoimidazole ribonucleotide carboxylase (AIRC) cDNA encoding a bifunctional enzyme of AIRC (EC 4.1.1.21) at step 6 and SAICAR synthetase (EC 6.3.2.6) at step 7 in de novo purine nucleotide synthesis was cloned and sequenced. The size of the cloned rat AIRC cDNA was 1329 bp, and amino acid identity with human and chicken AIRC was 96 and 85%, respectively. The intergenic sequence using a phage clone and the PCR product disclosed that ATase and AIRC genes are physically linked with the 736 bp sequence between the translation start sites, and the determination of the transcriptional start sites by the primer extension assay for these genes disclosed that distance between the two major transcriptional start sites is 585 bp. The amount of mRNAs of both genes showed approx. 5-6-fold increase in G1/S phase of the cell cycle over those in G0 phase in synchronized rat 3Y1 fibroblasts.
Hideo Kaneko, Kiyoko Sugita, Nobutaka Kiyokawa, Koho Iizuka, Koji Takada, Masahiro Saito, Katsuhiko Yoshimoto, Mitsuo Itakura, Yasuo Kokai and Junichiro Fujimoto : Lack of CD54 Expression and Mutation of p53 Gene Relate to the Prognosis of Childhood Burkitt's Lymphoma., Leukemia and Lymphoma, Vol.18, 179-184, 1995.
115.
Yasumi Shintani, Katsuhiko Yoshimoto, Hideaki Horie, Toshiaki Sano, Yoshiko Kanesaki, Emiko Hosoi, Yutaka Yokogoshi, Hiroshi Bando, Hiroyuki Iwahana, Seiji Kannuki, Keizo Matsumoto, Mitsuo Itakura and Shiro Saito : Two Different Pituitary Adenomas in a Patient with Multiple Endocrine Neoplasia Type 1Associated with Growth Hormone-Releasing Hormone-Producing Pancreatic Tumor: Clinical and Genetic Features., Endocrine Journal, Vol.42, No.3, 331-340, 1995.
(要約)
The clinical and genetic features of a 43-year-old male patient with multiple endocrine neoplasia type 1 were reported. He developed hyperparathyroidism, a GHRH-producing pancreatic tumor, and acromegaly between 1980 and 1983. Because his pituitary gland increased in size even after resecting the GHRH-producing pancreatic tumor, transsphenoidal hypophysectomy was performed six years later. The pituitary contained two histologically-different adenomas composed of somatotroph cells and null cells. Genetic analyses revealed loss of heterozygosity on chromosome 11 in common in the pituitary adenomas, the pancreatic endocrine tumors, and a parathyroid hyperplasia. On the other hand, mutations of ras, p53, Gs alpha, and Gi2 alpha genes were not found in these tumors. The loss of the tumor suppressor gene on chromosome 11q12-13 was involved in the formation of two pituitary adenomas, two pancreatic endocrine functioning tumors, and a parathyroid hyperplasia in this patient, but the tumorigenic factors in the specific endocrine organs remain to be studied.
(キーワード)
Acromegaly / Adenoma / Adult / Base Sequence / Chromosomes, Human, Pair 11 / DNA Mutational Analysis / Genes, Tumor Suppressor / Growth Hormone-Releasing Hormone / Heterozygote / Humans / Hyperparathyroidism / Male / Molecular Sequence Data / Multiple Endocrine Neoplasia Type 1 / Pancreatic Neoplasms / Pituitary Neoplasms / Polymorphism, Restriction Fragment Length
Katsuhiko Yoshimoto, Chisato Kosugi, Sachiko Hamaguchi, Takehiko Kimura, Hiroyuki Iwahana, Akira Miyauchi and Mitsuo Itakura : Tumor-Specific Mutations in the Tyrosine Kinase Domain of the RET Proto-Oncogene in Pheochromocytomas of Sporadic Type., Endocrine Journal, Vol.42, No.2, 265-270, 1995.
(要約)
Sporadic pheochromocytomas, sporadic medullary thyroid carcinomas (MTCs), pheochromocytomas and/or MTCs in multiple endocrine neoplasia (MEN) 2A or 2B were screened for mutations in the tyrosine kinase domain of the RET proto-oncogene by direct sequencing of PCR-amplified products or sequencing subcloned DNAs from PCR-products. All tumors of 4 MEN 2B patients were confirmed to contain a heterozygous missense mutation at codon 918 (ATG-->ACG; Met-->Thr) of the RET proto-oncogene as well as their leukocytes. The same tumor-specific mutations at codon 918 were also found in 5/16 (31%) sporadic pheochromocytomas. These results suggest that mutations of the RET proto-oncogene in its tyrosine kinase domain play a role not only as the predisposing gene for MEN 2B, but also as a tumorigenic factor for pheochromocytomas of sporadic type.
Masaki Tanaka, Kyo Adzuma, Miki Iwami, Katsuhiko Yoshimoto, Yasumasa Monden and Mitsuo Itakura : Human Calgizzarin; One Colorectal Cancer-Related Gene Selected by a Large Scale Random cDNA Sequencing and Northern Blot Analysis., Cancer Letters, Vol.89, 195-200, 1995.
Masaki Tanaka, Rumi Katashima, Daisuke Murakami, Kyo Adzuma, Yoko Takahashi, Akira Tomonari, Hiroyuki Iwahana, Katsuhiko Yoshimoto and Mitsuo Itakura : Molecular Cloning of a Group of Mouse Pancreatic Islet B Cell and Glucose Concentration-Related Genes by Random cDNA Sequencing., Diabetologia, Vol.38, 381-386, 1995.
121.
Yoshiaki Kubo, Yoshio Urano, Katsuhiko Yoshimoto, Hiroyuki Iwahana, Kosaku Fukuhara, Seiji Arase and Mitsuo Itakura : p53 Gene Mutations in Human Skin Cancers and Precancerous Lesions: Comparison with Immunohistochemical Analysis., The Journal of Investigative Dermatology, Vol.102, No.4, 440-444, 1994.
122.
Maki Moritani, Katsuhiko Yoshimoto, Fumi Tashiro, Chikara Hashimoto, Jun-ichi Miyazaki, Setsuko Ii, Eiji Kudo, Hiroyuki Iwahana, Yoshio Hayashi, Toshiaki Sano and Mitsuo Itakura : Transgenic Expression of IL-10 in Pancreatic Islet A cells Accelerates Autoimmune Insulitis and Diabetes in Non-Obese Diabetic Mice., International Immunology, Vol.6, No.12, 1927-1936, 1994.
123.
Hiroyuki Iwahana, Toshiyuki Tsujisawa, Rumi Katashima, Katsuhiko Yoshimoto and Mitsuo Itakura : PCR with End Trimming and Cassette Ligation: A Rapid Method to Clone Exon-Intron Boundaries and a 5'-Upstream Sequence of Genomic DNA Based on a cDNA Sequence., Genome Research, Vol.4, No.1, 19-25, 1994.
124.
Hiroyuki Iwahana, Katsuhiko Yoshimoto, Toshiyuki Tsujisawa and Mitsuo Itakura : T-Cassette Ligation: A Method for Direct Sequencing and Cloning of PCR-Amplified DNA Fragments., Genome Research, Vol.3, 219-224, 1994.
Hiroyuki Iwahana, Noriko Mizusawa, Setsuko Ii, Katsuhiko Yoshimoto and Mitsuo Itakura : An End-Trimming Method to Amplify Adjacent cDNA Fragments by PCR., BioTechniques, Vol.16, No.1, 94-98, 1994.
127.
Katsuhiko Yoshimoto, Hiroyuki Iwahana and Mitsuo Itakura : Relatively Good Prognosis of Multiple Endocrine Neoplasia Type 2B in Japanese: Review of Cases in Japan and Analysis of Genetic Changes in Tumors., Endocrine Journal, Vol.40, No.6, 649-657, 1993.
(要約)
Since 1968, a total of 23 patients with multiple endocrine neoplasia type 2B (MEN 2B) have been identified in Japan. The mean age at diagnosis was 20.3 years (range, 6 to 39 years). All patients had neuromas and bumpy lips. All patients underwent thyroidectomy for medullary thyroid carcinoma (MTC). Ten of 23 patients had pheochromocytomas. One patient died of cerebral bleeding at the age of 43, 2 patients died of MTC at the age of 35 and 12. Five-, 10-, and 15-year survival rates were 100%, 92%, and 88%, respectively. The clinical course of MTC in MEN 2B in Japanese is not so aggressive when compared with about a 50% 10-year survival reported for Caucasians. Genetic analysis of 4 MTC and 1 pheochromocytoma from 4 patients with MEN 2B revealed no common changes in regard to loss of heterozygosity on 21 chromosomes or point mutations of the ras, Gs alpha, or p53 genes.
(キーワード)
Adolescent / Adrenal Gland Neoplasms / Adult / Asian Continental Ancestry Group / Carcinoma, Medullary / Cerebral Hemorrhage / Child / Chromosome Aberrations / Chromosomes, Human, Pair 10 / European Continental Ancestry Group / Female / Genes, p53 / Genes, ras / Humans / Japan / Lip Neoplasms / Male / Multiple Endocrine Neoplasia Type 2b / Neuroma / Pheochromocytoma / Prognosis / Survival Rate / Thyroid Neoplasms
Eiji Kudo, Kunio Ii, Hiroyuki Iwahana, Katsuhiko Yoshimoto, Kazuo Hizawa and Mitsuo Itakura : PCR-SSCP Screening of b-Amyloid Precursor Protein Mutations in Two Japanese Pedigrees with Familial Early Onset Alzheimer's Disease., Biomed Res, Vol.14, No.3, 223-231, 1993.
Katsuhiko Yoshimoto, Hiroyuki Iwahana, Ayumi Fukuda, Toshiaki Sano, Shiro Saito and Mitsuo Itakura : Rare Mutation of Gs Alpha Subunit Gene in Human Endocrine Tumors: Mutation Detection by Polymerase Chain Reaction-Primer-Introduced Restriction Analysis., Cancer, Vol.72, No.4, 1386-1393, 1993.
(要約)
The Gs alpha (Gs alpha) gene can be activated to the putative oncogene gsp by specific point mutations at codons 201 or 227. Such mutations have been reported in growth hormone (GH)-secreting pituitary adenomas and thyroid tumors. To clarify the role of Gs alpha gene in human endocrine tumors, 197 tumors were screened for point mutations at codons 201 or 227 of the Gs alpha gene. Mutations were detected by primer-introduced restriction analysis (PIRA) of the polymerase chain reaction (PCR) product of genomic DNA. These Gs alpha mutations were present in 4 of 53 pituitary adenomas (4 of 43 GH-secreting adenomas; 1 of these 4 was a GH- and prolactin-secreting adenoma from a patient with familial multiple endocrine neoplasia Type 1), 4 of 66 thyroid tumors (4 of 30 papillary carcinomas), and 1 of 19 adrenocortical adenomas (1 of 6 aldosterone-secreting adenomas). In contrast, none of these Gs alpha mutations were detected in parathyroid tumors, endocrine pancreatic tumors, or pheochromocytomas. Gs alpha mutations at these two loci may play a role in the pathogenesis of a small population of GH-secreting pituitary adenomas, papillary thyroid carcinomas, and adrenocortical adenomas, but that they are not involved in the pathogenesis of other types of endocrine tumors.
Hiroyuki Iwahana, Takashi Yamaoka, Masakazu Mizutani, Noriko Mizusawa, Setsuko Ii, Katsuhiko Yoshimoto and Mitsuo Itakura : Molecular Cloning of Rat Amidophosphoribosyltransferase., The Journal of Biological Chemistry, Vol.268, No.10, 7225-7237, 1993.
131.
Hiroyuki Iwahana, Jun Oka, Noriko Mizusawa, Eiji Kudo, Setsuko Ii, Katsuhiko Yoshimoto, Edward W Holmes and Mitsuo Itakura : Molecular Cloning of Human Amidophosphoribosyltransferase., Biochemical and Biophysical Research Communications, Vol.190, No.1, 192-200, 1993.
132.
Katsuhiko Yoshimoto, Hiroyuki Iwahana, Ayumi Fukuda, Toshiaki Sano, Kiyonori Katsuragi, Moritoshi Kinoshita, Shiro Saito and Mitsuo Itakura : Ras Mutations in Endocrine Tumors: Mutation Detection by PCR-SSCP., Japanese Journal of Cancer Research, Vol.83, No.10, 1057-1062, 1992.
Hiroyuki Iwahana, Katsuhiko Yoshimoto, Toshio Shigekiyo, Akira Shirakami, Shiro Saito and Mitsuo Itakura : Molecular and Genetic Analysis of a Compound Heterozygote for Dysprothrombinemia of Prothrombin Tokushima and Hypoprothrombinemia., American Journal of Human Genetics, Vol.51, 1386-1395, 1992.
134.
Akira Tomonari, Hiroyuki Iwahara, Katsuhiko Yoshimoto, Toshio Shigekiyo, Shiro Saito and Mitsuo Itakura : Two New Nonsense Mutations in Type Ia Antithrombin III Deficiency at Leu 140 and Arg 197., Thromb Haemostas, Vol.68, No.4, 455-459, 1992.
135.
Hiroyuki Iwahana, Noriko Mizusawa, Katsuhiko Yoshimoto and Mitsuo Itakura : Detection of a New Polymorphism of the Human Prothrombin (F2) Gene by Combination of PASA and Mutated Primer-Mediated PCR-RFLP., Human Genetics, Vol.90, 325-326, 1992.
136.
Katsuhiko Yoshimoto, Hiroyuki Iwahana, Ayumi Fukuda, Shiro Saito and Mitsuo Itakura : Role of p53 Gene Mutations for Endocrine Tumorigenesis: Mutation Detection by Polymerase Chain Reaction-Single Strand Conformation Polymorphism., Cancer Research, Vol.52, No.18, 5061-5064, 1992.
137.
Hiroyuki Iwahana, Katsuhiko Yoshimoto and Mitsuo Itakura : Highly Polymorphic Region of the Human Prothrombin (F2) Gene., Human Genetics, Vol.89, No.1, 123-124, 1992.
138.
Hiroyuki Iwahana, Katsuhiko Yoshimoto and Mitsuo Itakura : Detection of a Single Base Substitution of the Gene for Prothrombin Tokushima: The Application of PCR-SSCP for the Genetic and Molecular Analysis of Dysprothrombinemia., International Journal of Hematology, Vol.55, No.1, 93-100, 1992.
(要約)
The genetic and molecular basis of a mutant prothrombin of 'prothrombin Tokushima' was studied by polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) and PCR-restriction fragment length polymorphism (PCR-RFLP) analyses. The abnormal gene was detected by altered migration by PCR-SSCP and by the loss of an MspI site by PCR-RFLP. The gene for prothrombin Tokushima was shown to be inherited from the mother of the proband. Sequencing analysis using PCR-amplified genomic DNA clarified a substitution of thymine (T) for cytosine (C) at position 9,490, changing arginine (Arg) to tryptophan (Trp) at position 418 of the polypeptide chain. This point mutation is assumed to be the molecular basis of prothrombin Tokushima, firstly, because of the absence of distinct changes in Southern blot analysis of the proband's DNA (using a full-length human prothrombin cDNA as a probe), secondly, because it has the same molecular weight as the abnormal gene product, and, thirdly, because of the absence of other amino acid abnormalities in the proteolytic peptide-fragments. It is concluded that PCR-SSCP and PCR-RFLP were useful for detecting the abnormal gene and for directly diagnosing the carrier status of dysprothrombinemia. This is the first report of gene analysis of dysprothrombinemia.
(キーワード)
Amino Acid Sequence / Base Sequence / Molecular Sequence Data / Mutation / Nucleic Acid Conformation / Polymerase Chain Reaction / Polymorphism, Genetic / Polymorphism, Restriction Fragment Length / Prothrombin
(文献検索サイトへのリンク)
● PubMed @ National Institutes of Health, US National Library of Medicine (PMID): 1349838
Hiroyuki Iwahana, Katsuhiko Yoshimoto and Mitsuo Itakura : Detection of Point Mutations by SSCP of PCR-Amplified DNA after Endonuclease Digestion., BioTechniques, Vol.12, No.1, 64-66, 1992.
140.
Katsuhiko Yoshimoto, Hiroyuki Iwahana, Katsuyuki Kubo, Shiro Saito and Mitsuo Itakura : Allele Loss on Chromosome 11 in a Pituitary Tumor from a Patient with Multiple Endocrine Neoplasia Type I., Japanese Journal of Cancer Research, Vol.82, 886-889, 1991.
single nucleotide polymorphisms / SNPs,association analysis / case control study / disease-susceptibility gene / functional genomics / polygenic diseases
V Bolduc, G Marlow, TC Conte, R Larivière, KM Boycott, K Saleki, Hiroshi Inoue, J Kroon, Mitsuo Itakura, Y Robitaille, L Parent, F Baas, K Mizuta, Nobuyuki Kamata, I Richard, WHJP Linssen, I Mahjneh, M Visser de, R Bashir and B Brais : Recessive mutations in the putative calcium-activated chloride channel Anoctamin 5 cause proximal LGMD2L and distal MMD3 muscular dystrophies, 5th International Congress of the World Muscle Society, Oct. 2010.
2.
V Bolduc, G Marlow, KM Boycott, TC Conte, R Larivière, K Saleki, Hiroshi Inoue, J Kroon, Mitsuo Itakura, Y Robitaille, L Parent, F Baas, K Mizuta, Nobuyuki Kamata, I Richard, WHJP Linssen, I Mahjneh, M Visser de, R Bashir and B Brais : Recessive mutations in the putative calcium-activated chloride channel Anoctamin 5 cause proximal LGMD2L and distal MMD3 muscular dystrophies, The Ottawa Conference on New Directions in Biology & Disease of Skeletal Muscle, May 2010.
3.
Takeo Iwata, Masamichi Kuwajima, Akiko Sukeno, Naozumi Ishimaru, Yoshio Hayashi, M Wabitsch, Noriko Mizusawa, Mitsuo Itakura and Katsuhiko Yoshimoto : YKL-40 secreted from macrophages infiltrating into adipose tissue inhibits degradation of type I collagen., International symposium on diabetes, Tokyo, Mar. 2009.
4.
Parvaneh Keshavarz, Hiroshi Inoue and Mitsuo Itakura : Genetic Variations in the TORC2 Gene Are Not Associated with Type 2 Diabetes in Japanese., The ASHG annual meeting in 2006, New Orleans, 2006.
5.
Toshihito Tanahashi, Dai Osabe, Kyoko Nomura, Syuichi Shinohara, Hitoshi Kato, Tatsuro Miyamoto, Yoichiro Takata, Kiyoshi Kunika, Maki Moritani, Hiroshi Inoue and Mitsuo Itakura : A dense SNPs map of human chromosome 20q11.21-13.13: linkage disequilibrium pattern, haplotype analysis, and association with type 2 diabetes in a 19.3 Mb interval, Keystone Symposia, 2006.
6.
Mitsuo Itakura : Allele frequency database in asian SNPs and gene-centric even-spacing common SNPs probes available for high efficiency case-control associationstudy, International Symposium of Genome Variations and Disease Association, Seoul, 2004.
7.
Mitsuo Itakura : Search for the Disease Susceptibly Genes of Type 2 Diabetes and Rheumatoid Arthritis by Locus-wide Association Analysis in Japanese, 9. 5th HUGO Pacific Meeting & 6th Asia Pacific Conference on Human Genetics, Singapore, 2004.
8.
Yamasaki Hiroyuki, Noriko Mizusawa, Shinji Nagahiro, Shozo Yamada, Toshiaki Sano, Mitsuo Itakura and Katsuhiko Yoshimoto : GH-secreting pituitary adenomas infrequently contain inactivating mutations of PRKAR1A and LOH of 2p16 and 17q23-24., 85th annual meeting of the endocrine society, Philadelphia, Jun. 2003.
9.
Mitsuo Itakura : Efficient Discovery of Disease Susceptibility Genes with Newly Developed Gene-Centric Even-Spacing Common Shared SNPs Markers, --- Toward the Genomic Drug Discovery for Diabetes ---, Fifth AFMC International Medicinal Chemistry Symposium, Kyoto, 2003.
10.
Mitsuo Itakura : Efficient Discovery of Disease Susceptibility Genes with Newly Developed Gene-Centric Even-Spacing Common Shared SNPs Probes - Application to Diabetes, 7. The 5th International Workshop on Advanced Genomics, Yokohama, 2003.
11.
Toshinori Sakai, Shinsuke Katoh, Koichi Sairyo, Chisato Tanaka, Rumi Katashima, Katsuhiko Yoshimoto and Mitsuo Itakura : An SNP in the 3region of the Collagen11 Alpha 2 Gene is Associated with Susceptibility to OPLL., 47th Annual Meeting of Orthopaedic Research Society, San Francisco, Feb. 2001.
12.
Hiroko Hagiwara, Kazumi Sawakami, Midori Yamamoto, Hideji Tajima, Shouji Iwasaki, Masato Kobori, Mitsuo Itakura, Yousuke Takahama and Masayuki Machida : Development of an automated system for the analysis of SNPs using the MagtrationR technology, 6. Genome Sequencing and Analysis Conference, San Diego, 2001.
13.
Mitsuo Itakura : SNP-Based Genetic Epidemiological Strategy to Find Disease-Related Genes in Japan, The 2nd International Symposium on Host Genetic Epidemiology, Seoul, 2001.
14.
T. Abe, Katsuhiko Yoshimoto, M. Taniyama, K. Hanakawa, H. Izumiyama, Mitsuo Itakura and K. Matsumoto : A Germline Mutation of the Multiple Endocrine Neoplasia Type 1 (MEN1) Gene in Japanese Prolactinoma Variant of MEN1., Annual Meeting of the American Association of Neurological Surgeons, San Francisco, Apr. 2000.
15.
Mitsuo Itakura : Candidate Approach and Positional Candidate Approach to Polygenic Diseases, The 3rd International Workshop on Advanced Genomics, Yokohama, 2000.
16.
Mitsuo Itakura, Maki Moritani, Setsuko Ii, Takashi Yamaoka, Hiroyuki Iwahana and Katsuhiko Yoshimoto : Approaches to Develop Gene Therapy for Diabetes., The 12th International Symposium of Federation of Asian and Oceanian Biochemists and Molecular Biologists: Gene Regulation of Biological Functions, Tokushima, Jul. 1996.
17.
Setsuko Ii, M. Ohta, Y. Takahashi, Y. Tano, Y. Kokai, Hiroyuki Iwahana, Katsuhiko Yoshimoto and Mitsuo Itakura : Effect of Transgenic Expression of Aldose Reductase (AR) on Diabetic Proteinuria and Retinopathy., The 15th International Diabetes Federation Congress, Kobe, Nov. 1994.
18.
A. Tomonari, Katsuhiko Yoshimoto, M. Tanaka, Hiroyuki Iwahana and Mitsuo Itakura : Cis-Elements of Human Insulin Gene Involved in Glucose-Responsive Transcription in a Mouse Islet B Cell Line of MIN6., The 15th International Diabetes Federation Congress, Kobe, Nov. 1994.
19.
M. Tanaka, Rumi Katashima, D. Murakami, A. Tomonari, Hiroyuki Iwahana, Katsuhiko Yoshimoto and Mitsuo Itakura : Molecular Cloning of a Group of Pancreatic Islet B cell- and Glucose Concentration-Specific Genes by Random cDNA Sequencing., The 15th International Diabetes Federation Congress, Kobe, Nov. 1994.
20.
Maki Moritani, Katsuhiko Yoshimoto, Hiroyuki Iwahana and Mitsuo Itakura : Effect of IL-10 on Immunological Rejection of Islet B cells by Lymphocytes., The 15th International Diabetes Federation Congress, Kobe, Nov. 1994.
21.
J. Miyazaki, C. Hashimoto, F. Tashiro, Maki Moritani, Katsuhiko Yoshimoto and Mitsuo Itakura : Early-Onset Diabetes Induced in NOD Mice by Transgenic Expression of IL-10 in A cells or SV40 T antigen in B cells., The 15th International Diabetes Federation Congress, Satellite Symposium, "Lessons from Animal Diabetes", Oomiya, Nov. 1994.
22.
Kunio Ii, Eiji Kudo, K. Hizawa, Hiroyuki Iwahana, Katsuhiko Yoshimoto, Setsuko Ii and Mitsuo Itakura : Early Onset Familial Alzheimer's Disease (AD) in the Largest Family with AD in Japan. - Histopathological, Immunohistochemical and Amyloid Precursor Protein (APP) Gene Analysis Studies., The XIIth International Congress of Neuropathology, Toronto, Sep. 1994.
23.
Maki Moritani, Katsuhiko Yoshimoto, J. Miyazaki, F. Tashiro, Setsuko Ii, Eiji Kudo, Hiroyuki Iwahana, Yoshio Hayashi, Toshiaki Sano and Mitsuo Itakura : (Workshop) Local Production of IL-10 in Pancreatic Islet A-Cells in Transgenic NOD Mice Accelerates Autoimmune Insulitis and Diabetes., Combined Meeting of the 8th International Lymphokine Workshop and The 4th International Workshop on Cytokines, Osaka, Oct. 1993.
24.
Katsuhiko Yoshimoto, K. Kubo, Hiroyuki Iwahana, R. Yamasaki, Shiro Saito and Mitsuo Itakura : Molecular Basis for Tumorigenesis in Multiple Endocrine Neoplasia (MEN), FRONTIERS IN MOLECULAR ENDOCRINOLOGY" in GUNMA INTERNATIONAL ENDOCRINE SYMPOSIUM, Maebashi, Jan. 1991.
Natsumi Kangawa, Hiroshi Inoue, Yukiko Yamashita, Mitsuo Itakura, Tsutomu Ogata and Kenji Fujieda : Identification and functional analysis of novel human growth hormone-releasing hormone receptor (GHRHR) gene mutations in Japanese subjects with short stature (SS), 14th International Congress of Endocrinology (ICE2010), Mar. 2010.
6.
Hiroshi Inoue, Yukiko Yamashita, Mitsuo Itakura, Tsutomu Ogata and Kenji Fujieda : Identification and functional analysis of novel human growth hormone secretagogue receptor type 1a variants in Japanese subjects with short stature., 14th International Congress of Endocrinology (ICE2010), Mar. 2010.
Masateru Sakuramoto, Hiroshi Yamamoto, Ryo Saito, Toshinori Nakayama, Hiroshi Takaku, Mitsuo Itakura and Kahoko Hashimoto : The function of the exocyst complex member; Sec8 Molecules in the antigen presenting cells., 日本免疫学会総会・学術集会, 2008.
15.
田口 純, 斉藤 諒, 山本 絋士, 桜本 昌輝, 中村 俊憲, Mitsuo Itakura and 橋本 香保子 : The involvement of Sec8 Molecule; a subunit of exocyst complex, which supports vesicles transportation, for activating process of B cell., 日本免疫学会総会・学術集会, 2008.
Shusuke Numata, Shu-ichi Ueno, Junichi Iga, Ken Yamauchi, Hongwei Song, Ryota Hashimoto, Masatoshi Takeda, Hiroshi Kunugi, Mitsuo Itakura and Tetsuro Ohmori : TGFBR2 gene expression and genetic association with schizophrenia, The 29th Annual Meeting of Japanese Society of Biological Psychiatry, Jul. 2007.
板倉 光夫, 森谷 眞紀, 山岡 孝, 伊井 節子, 吉本 勝彦 : Strategy of SNPs-based discovery of disease-related genes as the possible targets of drug development,, 第73回日本薬理学会(横浜), 1999年5月.